: Upgraded Rear Diff - DTE Bows out Gracefully



wildwhl
05-02-05, 02:04 PM
I had sent the previously used/abused diff unit to Phil @ DTE to see if there was anything they could come up with. Below are a couple of email exchanges in that regard:


"Hello WW,

We have spent a considerable amount of time in engineering with the
differential you sent, investigating if/how there is anything DTE can offer
to add structural strength to the Getrag Differential in the Cadillac CTS-V
in its current design build.

There are quite a number of inherent weaknesses we have observed/identified
for this vehicle application in how the differential is built from the
manufacturer and how it is integrated into the vehicle's chassis. Due to
those inherent weaknesses of the assembly and implementation of the unit in
the chassis as a whole, we feel that any sort of internal modification/HD
component design by DTE to add structural differential case/internal
component strength would be thwarted by the poor environment the
differential must operate in within the wheel-hop, chassis-deflection prone
2004-2005 Cadillac CTS-V. Additionally, this unit is just FAR to
lightweight to provide enough support for HP applications of any kind no
matter what is modified/altered to provide additional strength in the O.E.
differential configuration from Getrag.

We would have the ability to adapt the C5 Corvette differential into the
2004-'05 Cadillac CTS-V with very durable results, as many of our HP
differentials are successfully living behind many 9-second Corvette's to
this day. The cost will be much more expensive for this route, but very
durable non-the-less. Due to the VERY low production volumes of the
Cadillac CTS-V and the high cost of R&D for a venture of this type, the
final cost for such an upgrade may or may not be what a typical Cadillac
CTS-V owner would be willing to spend from our experience with the vehicle
thus far. We estimate final costs to be somewhere in the 3000-4500 range
and the upgrade would have to be completed here in-house due to the heavy
fabrication and complexity of the upgrade. If enough people were *serious*
about an upgrade such as this, we would certainly proceed forward with this
venture.

At this point however, there is nothing we can do (or are willing to- due
to negative liability issues DTE would face) to upgrade the 2004-2005
Cadillac CTS-V Getrag Differential at this time. Unfortunately, this
differential is a victim of its own design from an aftermarket standpoint
and any sort of strengthening devices for it would be somewhat pointless to
some extent due to it's frail overall design for this V8-powered
application.

We'll put the unit back together for you and send it back. Thank you for
the opportunity to let DTE look at it."


Best Wishes and God Bless,
Phil Rickard- President

**********************************


<Phil-

Thank you so much for your time and effort on this unit. I really
appreciate your thoughtful insight and feedback.

Would you mind if I post your respose on the Cadillac Forum(s), or would
you prefer to enlighten V enthusiast directly?

Thanks again,

Wildwhl>

"Hi WW,
Sure, go ahead. It would save me a BUNCH of typing. :-)"

Best Wishes and God Bless,
Phil Rickard- President
Dynotech Engineering, Inc.
www.dynotech-eng.com
(260)407-5455 ext. 11

benjet
05-02-05, 02:31 PM
I bet this is gonna become a most viewed thread FAST.

I just wanted ot have the 1st reply in (hehe) and say thanks again to those @ DTE for looking into this and the time spending thier valuable time with us enthusiasts.

Hats off to DTE!

lasstss
05-02-05, 02:31 PM
Big surprise. I guess we all know its a POS to begin with made for a 6 cyl car.

Perhaps a group buy with the C-5 set up is the ticket. I would be happier doing that than a blower..

wildwhl
05-02-05, 02:39 PM
Big surprise. I guess we all know its a POS to begin with made for a 6 cyl car.

Perhaps a group buy with the C-5 set up is the ticket. I would be happier doing that than a blower..

I don't know, lasstss, but getting blown is pretty awesome :)

I have to agree, though, as I'm not driving the car the way I should be able to with the blower on. I just have this feeling that the rear diff is not going to hang if I do :banghead:

That's OK, the MagnaCharger still rocks where the V performs best - at speed.

I want to publicly thank Phil and the staff of DTE for their efforts :worship:

willsctsv
05-02-05, 03:01 PM
For 06,Maybe GM will get Getrag to make a Steel unit instead of aluminum. Then the part #'s will change, and anyone that blows the rear in there 04/05 V will get the new rear installed. So, not everyone will need it, but those that blow it up will get the upgraded one..

Brilliant! I hope there listening.
Otherwise this car will fizzle out faster than we can drive em to 60 MPH!

V-seriesTech
05-02-05, 03:19 PM
told you guys the C5 diff would work. I think I have one too...

Dynotech Engineering
05-02-05, 03:53 PM
We suspect GM/Getrag will more than likely implement a running change to their differential design in regards to durability for this platform which can be retro-fitted to the older models with much more ease and less overall cost.

Once Getrag engineeres a stronger platform to start with, we'll then once again take a look at that unit and upgrade the internals from there to support the increasing power levels of the Cadillac CTS-V just as we have for the heavy-hitting C5 Corvette racers.

GM/Getrag can't ignore this negative issue forever and I'm sure it can't be any good for their image either...


Best Regards,
Phil- DTE

StealthV
05-02-05, 03:55 PM
:helpless:

Dynotech Engineering
05-02-05, 04:16 PM
EDIT: This response was directed to StealthV in regards to him suggesting to use a cast iron case. For whatever reason, he chose to delete/alter his post after we responded to his post......:hmm: :rolleyes2
Just to clarify for those that may be confused. :)


There is MUCH more to this overall design weakness than just case material and a cast iron version would not matter in the least from a durability standpoint, other than adding additional wieght to an already heavy vehicle....... We've been down that road LONGGGGGGGG ago before.

Oversimplified....
The unit does hold enough lubricant to provide adequete cooling/lubricating/cleaning properties to be effective for any serious HP use...

The bearings are WAYYYY to small in size and effective bearing-roller surface area to support any sort of *real* heavy torque loads from increased power input...

The differential mouting pick-up points of attachment are VERY poor and the chassis flexes so severely under load, it's really a wonder these current differentials last as long as they do....

The output shaft axles of the differential itself are even smaller in diamater and spline-count than the C5 Corvette counterparts...

The differential has no *real* support of any kind within the CTS-V's flex-prone chassis, overly-soft mounting bushings, poor pinion angle geometery, odd rear bearing hub/spindle configuration, (which is a MAJOR source of the wheel hop issue BTW) therefore the wheel hop damage would occur just as frequently with cast iron as it does with aluminum...

The CTS-V axles/inner CV joints are also smaller than the C5 Corvette counterparts...


Needless to say, a cast iron case isn't worth the paper is was designed on if the periphreal components used in it's build or chassis support configuration are not up to the task of effectively supporting any *real* type of input power.

Our hope is that GM does not only introduce a stronger case design of whatever material, but to also upgrade the surrounding internal/external components as well as a complete package- not just a band-aid fix that just a cast iron case only would be.....


DTE

JBeechel
05-02-05, 04:28 PM
Someone needs to mention this in the next GM survey.

2005V
05-02-05, 04:57 PM
I'm in for the group buy!

Joey'sVee
05-02-05, 05:16 PM
There is MUCH more to this overall design weakness than just case material and a cast iron version would not matter in the least from a durability standpoint, other than adding additional wieght to an already heavy vehicle....... We've been down that road LONGGGGGGGG ago before.

Oversimplified....
The unit does hold enough lubricant to provide adequete cooling/lubricating/cleaning properties to be effective for any serious HP use...

The bearings are WAYYYY to small in size and effective bearing-roller surface area to support any sort of *real* heavy torque loads from increased power input...

The differential mouting pick-up points of attachment are VERY poor and the chassis flexes so severely under load, it's really a wonder these current differentials last as long as they do....

The output shaft axles of the differential itself are even smaller in diamater and spline-count than the C5 Corvette counterparts...

The differential has no *real* support of any kind within the CTS-V's flex-prone chassis, overly-soft mounting bushings, poor pinion angle geometery, odd rear bearing hub/spindle configuration, (which is a MAJOR source of the wheel hop issue BTW) therefore the wheel hop damage would occur just as frequently with cast iron as it does with aluminum...

The CTS-V axles/inner CV joints are also smaller than the C5 Corvette counterparts...


Needless to say, a cast iron case isn't worth the paper is was designed on if the periphreal components used in it's build or chassis support configuration are not up to the task of effectively supporting any *real* type of input power.

Our hope is that GM does not only introduce a stronger case design of whatever material, but to also upgrade the surrounding internal/external components as well as a complete package- not just a band-aid fix that just a cast iron case only would be.....


DTE

Sounds like someone has done a little research and knows their stuff! :worship:

Florian
05-02-05, 05:29 PM
Phil, for 10Gs would you consider a rear end/maggie package? :yup:

Florian

alcindus
05-02-05, 05:41 PM
hell yes i would

c5racr1
05-02-05, 06:08 PM
DTE what about this for 2700.00 US, Used for the 2004 up GTO, I am really leaning toward this set up.

DILLIGAF
05-02-05, 06:17 PM
Theres alot of us in here who would commit to a group buy if it's THE fix i'm sure.16000 miles no problem yet,nock on wood.I'd get it out of there in a heartbeat if something better became available.With the maggie on when it goes i'm probably on my own anyway.

Dynotech Engineering
05-02-05, 06:19 PM
Any of those types of differentials could be made to adapt into the Cadillac chassis, but the fabrication involved to facilitate it's use is not only VERY challenging, but the costs can escalate to, or near the range we listed above earlier, not to mention specially-made axle assembles to adapt to the Cadillac spindles/hubs, exhaust system modification, rear sub-frame modification, properly engineered differential supports that don't transmit excessive noise back into the passenger cabin, etc, etc, etc.

The old saying of "Anything can be made to work if someone is willing to spend what it takes to do it" applies here. :cool: :bonkers:


Best Regards,
Phil- DTE

dannystang
05-02-05, 06:21 PM
I like $3000 for a bullet-proof rear end.

Delivered.

When would you like my credit-card number please?

V-seriesTech
05-02-05, 06:32 PM
Any of those types of differentials could be made to adapt into the Cadillac chassis, but the fabrication involved to facilitate it's use is not only VERY challenging, but the costs can escalate to, or near the range we listed above earlier, not to mention specially-made axle assembles to adapt to the Cadillac spindles/hubs, exhaust system modification, rear sub-frame modification, properly engineered differential supports that don't transmit excessive noise back into the passenger cabin, etc, etc, etc.

The old saying of "Anything can be made to work if someone is willing to spend what it takes to do it" applies here. :cool: :bonkers:


Best Regards,
Phil- DTE


I likle these guys...:lildevil:

JBeechel
05-02-05, 07:42 PM
3K is doable

Geno
05-02-05, 08:09 PM
I We estimate final costs to be somewhere in the 3000-4500 range
and the upgrade would have to be completed here in-house due to the heavy
fabrication and complexity of the upgrade.

Phil, I'm world serious. Are you talking about a C5 transaxle for 4.5 to 6, then I be over tomorrow.:D

GNSCOTT
05-02-05, 08:35 PM
Thanks for the info DTE. I tried explaining that it is not the material used, but the way it is used. THere are many alluminum rears out there that can handle 1500 ftlbs and are alluminum center sections. I also agree that the carrier was not the only problem and a cast one would not help much and could hurt with cooling. It would not only add weight, but throw off the critical weight distribution that caddy worked so hard to acheive.

I would hate to spend $3k and have Getrag come out with a new design in the 06, or even an adaptable one in the 07. GM will not want to keep replacing our rears and they will eventually have to get one in there that lasts.

Dynotech Engineering
05-02-05, 08:35 PM
Are you talking about a C5 transaxle for 4.5 to 6, then I be over tomorrow.

Correct, but I don't believe the cost would be quite that high. :)

When CTSVLS6 gets back from vacation, I'll inquire with him if he would let us look into it further using his car as the R&D vehicle, as we promised him that if we ever did follow this venture, his car would be first. We've discussed it many times in the past.

One must remember that any venture of prototyping specialized components such as HD driveline parts will require that the car be down for however long it takes to perfect something as radical as this, so I would understand if CTSVLS6 doesn't want to give up his car for the better protion of the summer to do this.... :o

I'll ask him, we'll see. :)


Best Regards,
Phil- DTE

Dynotech Engineering
05-02-05, 08:38 PM
I would hate to spend $3k and have Getrag come out with a new design in the 06, or even an adaptable one in the 07. GM will not want to keep replacing our rears and they will eventually have to get one in there that lasts.

I concur whole-heartedly! :) That's one of the reasons we've held off this long.


Best Regards,
Phil- DTE

Geno
05-02-05, 08:55 PM
Correct, but I don't believe the cost would be quite that high. :)

When CTSVLS6 gets back from vacation, I'll inquire with him if he would let us look into it further using his car as the R&D vehicle, as we promised him that if we ever did follow this venture, his car would be first. We've discussed it many times in the past.
Phil- DTE

Well here's to CTSVLS6 being up to it.:drinker
I live about a third of the country away from you, but I am very serious about getting the rear right regardless of what GM may do in the future. Us guy's with the major motor mods don't really get any benefit from installing a GM fix because they wouldn't warrant the rear in any case.

Thanks for considering picking up the gaunlet!:thumbsup:

lasstss
05-02-05, 08:58 PM
I would be suprised if GM makes a wholesale change and that it would bolt in. My money is on a redesign that wont fit!

However, DTE.... the entire bare cradle unit can be bought from GM for $600.00.. The C5 dif could be modled in without having the car tie up the shop. :thumbsup:

Geno
05-02-05, 09:02 PM
Consider this...GM may come up with a fix, but it's going to be the cheap solution and the fix (probably just a beefed diff unit) is going to be basic (read non-comprehensive).

As I understand DTE, their approach is holistic. :worship:

2004ctsv
05-02-05, 09:13 PM
Why should I have to pay $4K to fix a design flaw?
Why should I buy a new rearend from DTE to bring the car back to where it should be?

No offense, but I would pay for an upgrade, not a retro-fit.

I won't mind paying for a new diff that could match the power from adding a Magnuson blower. But I won't pay for a rear end that replaces a defective one that can't take the 400 hp that the car came with. GM should pay for that one.

And they will, over and over again.

This ain't your father's Oldsmobile, it's your grandmother's Cadillac. So drive it accordingly.

Tony

Playdrv4me
05-02-05, 09:13 PM
Boy, I sure hope GM steps up to the plate for you guys with this one, seems this Diff is COMPLETELY NOT UP TO THE TASK of supporting the V's power structure at all, and I certainly wouldnt want to dole out the cost of a nice new Rolex just to get a reliable rear end!

I think GMs definitely gonna implement some sort of running change that you guys will be able to retro back into your V's. I wish I knew why manufacturers have such a love affair with aluminum diffs. This was a huge problem with the D44AL in the Grand Cherokee as well, plenty of grenaded diffs with nothing more than every day driving, caused quite a few scares too.

GNSCOTT
05-02-05, 09:13 PM
I have to disagree. I really beleive GM and Getrag cannot afford to keep replacing rears (many now have 75-100k warranties) I am sure that they would somehow make it adaptable to our V's.

Geno
05-02-05, 09:33 PM
Why should I have to pay $4K to fix a design flaw?


Tony,
Let's start off by what I'm about to say is not a flame. :o
I understand your position, but I don't agree with it. True, GM should of got it right, but they didn't. You pay your money and you take your chances, sad but true.
There are three routes here as I see it:

For those that have stock motors, the first choice is to hold your breath and hope that a company that has major cash flow issues will retro fit your "V" with a proper fix.

For those that have a stock motor and just don't want to worry about the rear coming lose 500 miles from home, go aftermarket.

Choice three for those that have a modded motor, is to have the aftermarket come to the rescue. We want a rear we can punish without pausing to reflect each time we mash the GO pedal.

2004ctsv
05-02-05, 09:47 PM
Geno


We are going to differ here. If the AC doesn't get cold enough, then too bad. You'll survive that flaw.

A defective drive train? That could be fatal. And this web site will be fodder for the lawyers.

Yes sir, GM will pay over and over if (no, when) that happens.

Tony

Geno
05-02-05, 09:55 PM
Geno


We are going to differ here. If the AC doesn't get cold enough, then too bad. You'll survive that flaw.

A defective drive train? That could be fatal. And this web site will be fodder for the lawyers.

Yes sir, GM will pay over and over if (no, when) that happens.

Tony

Agreed!:disappoin

dannystang
05-02-05, 10:06 PM
Well I think I may have a cure.

I think I have perfected ruining the rear end. The secret is driving slowly since driving normally seems to do nothing.

If we all drive slowly for a month, and blow rears simultaneously (spelling sorry) that might send a signal to GM. If that doesnt work than the DTE fix goes in.

BTW my Car and Driver arrived with a big article on how they screwed the Ford GT with some shotty subbed out parts.

Maybe we should contact them?

CTSVLS6
05-02-05, 10:21 PM
I just got done reading this post. Very interesting. I am glad to see that there is so many of you guys interested in a real fix. GM replaced my first rear at 10300, the second at 10700 with a whine from the get go, and the third has 100 miles on it with a slight whine on decell. I think this is the best they have to offer and it is only a matter of time befor it gets nosey. Looks like the only real solutation is to call Phil and let him have at it.:worship: I'll be on the phone in the morning.

GNSCOTT
05-02-05, 10:28 PM
I don't think anyone has lost a rear in normal driving. I think all rear breakages happen when we try to duplicate GM's advertised 0-60 times> They are using that to spearhead their advertising campaighn (sp) so it should be alright for us to try our best to duplicate it every once in a while.

There is no problem as long as they don't give you a hard time when you go to get a new one installed.

Florian
05-02-05, 10:40 PM
Negative! I lost my rear just daily driving...no clutch drops, no crazy starts...just whine then failure.

Florian

jspinetto
05-02-05, 10:54 PM
Wouldn't the DTE solution for the diff be able to handle the power of the maggie ?

Jonathan

Vrocks
05-02-05, 11:15 PM
If some of us are willing to pay over 3 grand for a diff fix, why not spend it on a wheel hop fix? If we could stop the hop we'd lower the dynamic load on the rear cradle and diff, eliminating what looks to be a big factor in diff failure.

How much would it cost to do what Mallett did to the rear? For me, I'd rather have the guys at DTE fix the hop.

Florian
05-02-05, 11:19 PM
VRocks,

While I agree that the hop is a huge factor in the diff. failures, the bottom line is that the stock diff. isnt capable of handling the torque of the motor. This coupled with no real support of the cradle, soft mounting surfaces and many other mitigating factors are the problem. GM cheaped out on the Getrag crap and we are stuck with it. Id happily pay the 3-4K, get a bulletproof rearend and not worry about it all the time.
:rant2:
Florian

GAGS-V
05-02-05, 11:25 PM
All very interesting posts! So far I must be very lucky. I have a 2005 and have NEVER had any wheel hop of any sort. (2,500 mi. in two months) Hard starts, wet weather, hard turns, no problem. However, so many on here do have problems I sure want to keep up to date on what is going on. Anybody else out there lucky like I am? (with the wheel hop issue)

Vrocks
05-02-05, 11:26 PM
VRocks,

While I agree that the hop is a huge factor in the diff. failures, the bottom line is that the stock diff. isnt capable of handling the torque of the motor. This coupled with no real support of the cradle, soft mounting surfaces and many other mitigating factors are the problem. GM cheaped out on the Getrag crap and we are stuck with it. Id happily pay the 3-4K, get a bulletproof rearend and not worry about it all the time.
:rant2:
Florian
I agree.

I guess my view point is skewed at this point because I haven't had any problems. I just miss not being able to lay some rubber, in a straight line.

dannystang
05-02-05, 11:28 PM
I know alot of you guys see warranty as...Well great its fixed for free...

I KNOW I don't make annually what you guys do. As my daily driver and only having 1800 miles which maybe 50 were on hard acceleration. I am on rear 4. This TIME they figured it out...well tonight on my way to taco bell guess what I heard.

Now...between researching the net, going to the dealer, talking to god knows who...

I can tell you I would have made $3k EASIER (and I am poor) with less heartache.

Truly unbelivable my $2 dollar Jaguar lease makes this car seem like a Hyundai in comparison...10yr 100,000 miles of headache.

My .02 cents...

DILLIGAF
05-02-05, 11:40 PM
DTE,again R&D costs could be minimal if you have 50 guys commiting to purchase.Might not be that hard to get in here.Whats out there is gonna break sooner or later IMO.When and if caddy comes through with a fix it won't be for us with modded motors.Plenty of market for the taken IMO.

ta206
05-02-05, 11:40 PM
All very interesting posts! So far I must be very lucky. I have a 2005 and have NEVER had any wheel hop of any sort. (2,500 mi. in two months) Hard starts, wet weather, hard turns, no problem. However, so many on here do have problems I sure want to keep up to date on what is going on. Anybody else out there lucky like I am? (with the wheel hop issue)

I must be one of the lucky ones, too. No hop, no whine, no problems.
Unfortunately, I'm beginning to think that its only a matter of time...

Dave's V
05-03-05, 12:21 AM
Right now I would lean towards what kind of fix GM comes out with. I'm curious to see what happens when the car mags finish their long term tests on the V. Surely the rear end has to whine for them. I'm hoping they say something about it because that would put some pressure on Cadillac. Cadillac could not say there isn't a problem.

What will happen when the rear end is not the weakest link though? Do the gremlins move up the drivetrain to the driveshaft or tranny?

I believe Cadillac should and will do something about it. They can't afford not to do anything about it.

CTSV05
05-03-05, 12:56 AM
Well, as I've said before, Getrag is at fault for the faulty gear setups. Caddy is at fault for choosing them to build. We are somehow I'm sure at fault for enjoying our cars.

The wheelhop is totally fixable, could do it in an afternoon, well maybe a full day. BUT, I don't think too many here, myself included, are willing to ride around in a race-car quality ride.

Its easy, totally lock the cradle in, re-angle the shock posistion, and add shiocks with a ton of rebound. Just be prepared to gnash your teeth at every road imperfection.

Listen, I hope some type of reasonable fix shows up, but you all must understand the undertaking for any company to do this, its big.

I've had fantasies/dreams of machining a 9" pumpkin into a flange type rearend and building mounts to put in the car....wouldn't that rock!!!!

I'm not sure why Caddy didn't use a C5 case and axles, but they didn't.

Oh, BTW, the GTOs are out there hopping around too, so its not just us!

c5racr1
05-03-05, 01:45 AM
the picture i posted earlier is of a IRS Aluminum ford 9 inch case. It is installed in a 2004 holden monaro-GTO. I also think I may try ollking at a Irs from a 94-96 vette. dana 44 I believe. maby adapt the torque arm to center the rear and try to use the stock mounting locations. also has mini drive shafts insted of CV jounts.

lawfive
05-03-05, 03:18 AM
.

Flyboy
05-03-05, 07:09 AM
I have a "modified" 2005 V. Headers, cam, no cats, etc., etc. In other words...runs very well. I would definitely join in with some kind of a "group fix." My only concern (fear???) with this car is the differential. Car could be a "10" without that problem. Let's all keep this thought process moving along.

erp2863
05-03-05, 01:43 PM
Disclaimer: I know next to nothing about car rear ends!


In this months Motor Trend they mention the 2005 SSR gets a 14 bolt (9.5" ring gear) rear axel when mated to the manual tranny. The auto gets a 12 bolt w/ 8.6" ring gear.

Would these be options nobody has looked at or am I in the wrong ballpark? If anything, you can take from this that GM made changes after one model year on a car that is limited production.

Eric

riverrat
05-03-05, 03:32 PM
My rear blew at 300 miles no hard driving at all. A group buy at the $3000 level would be sweet and something many here could afford and would do. Just wanted to add to the list of the willing :eek:

dannystang
05-03-05, 03:42 PM
Someone post a poll for serious buyers..

lawfive
05-03-05, 03:44 PM
Phil,

If you build it, we will come.

lawfive
05-03-05, 03:45 PM
BTW: that was a "Field of Dreams" reference; I'm not suggesting anything inappropriate...

V-seriesTech
05-03-05, 04:04 PM
BTW: that was a "Field of Dreams" reference; I'm not suggesting anything inappropriate...



LOL

urbanski
05-03-05, 04:06 PM
Phil,

If you build it, we will come.word

r_casino
05-03-05, 05:25 PM
A group buy at the $3000 level would be sweet and something many here could afford and would do.

I'll tell you, from my perspective, it's not whether one can afford it or not...

Its whether one should pay $3000 to fix a part that apparently is not "right." I can understand a diff that failed on applications greater than 400 HP, but this thing apparently fails on the stock car routinely. I suppose I can understand spending $3000 to get a new diff that supports applications >400 HP for those choosing to do so. But, $3000 to "fix" what was supposed to already be working is a tough sell! (I mean that generally, not towards any vendor providing a solution.)

Maybe a $3000 diff is a solution for Cadillac to provide instead of the half-dozen stock diffs they'll be giving you over the warranty period (yeah, right.)

I can understand a new diff providing peace-of-mind, but, man, I have trouble getting past the idea that this should be my responsibility to fix!

More power to DTE if they provide a solution at any cost for those willing to buy.

Take care.

ahahnu
05-03-05, 05:38 PM
I wish I could dish out three gees to get a new rear, especially because mine is whining now. When I took my survey I was giving the car alot of 10s untill it came down to the questions of well made, well thought out, and complete. If I knew this was going to be such a big problem I wouldn't of bought it. This car is my daily driver, and I cannot afford a winter car. I wanted to do the AWK of CTSV05 and some other engine upgrades, but now- hell no. If its gonna void my warranty that I now NEED, forget it. That was another question in the survey, "Would you modify your car?"


Phil- this is a question for I guess everyone else, you mentioned too much body roll? or chasis flex? If one was to put on the stage three kit from CTSV05 would that make a major difference? I would like to know for my own knowledge also. Thank you in advance.

Dynotech Engineering
05-03-05, 05:52 PM
We have no idea if that product works or not, as we've never even seen one, installed one or tested one.

Just for clarification-
As far as the probable cost of a differential upgrade.... In my originaL post, I stated the range of cost to be somewhere in the $3000-$4500 range, depending on the level of fabrication required to adapt another differential type into the Cadillac CTS-V chassis. For some reason, everyone seems to have clung to the low-end cost of is modification as the "actual" cost to do such a thing, so we want to again iterate that there *is* a range of cost projection for a heavy modification such as this and we didn't want someone to get confused/upset if the cost of the upgrade exceeds the lower end of the scale. Of course, we'll do our best to keep overall costs down, but we really have no real solid cost projection thus far this early in the endeavor.

We hope no one got confused. :) :bouncy:

BeelzeBob
05-03-05, 06:37 PM
Just as a point of comparison....the Speedvision CTS-VR's run the stock diff with little or no problems so far. That is with over 500 HP and sticky tires. Granted the wheel hop is not an issue but the diff is not as weak or spindly as some would indicate.

I know that are all sorts of qualifiers and I realize that racing for an hour is not the same as street driving.....but.....the thing can take a fair amount of abuse without failing if treated properly. And it does get beat pretty hard in those cars not only during races but test and practice sessions as well. They are inspected frequently but have had no failures and they do NOT get a new diff each time out...

Hard to believe one falling apart in 300 miles of "normal" driving. And for a diff to start whining 500 miles after a new one was installed makes me think someone did not even give it a chance to break-in before hammering on it.... And, yes, I have put quite a few miles on a CTS-V and hammered on it unmercifully and have yet to see a rear go...and the last car I was in had well over 10K on it and was being used for "teaching" powershifting to the un-initiated. I just know better than to persist when wheel hop happens I guess.

The wheel hop issues and diff strength is no different that on many other cars in the past. One could destroy even a 12 bolt in a big block Chevelle or Camaro back in the 60's pretty easily with sticky tires. Anyone remember big block Corvettes spitting rear ends and half shafts when slicks were put on...?? Chrysler's muscle cars would wheel hop with sticky tires without clamping spring leaves and putting a pinion snubber on them and tear up the ring gear. Most people have forgotten about the "good ole days" I guess. The biggest change to today is that the tires are so much better that even the factory rubber provides more grip than you could get in the good ole days when the HP levels were similar. There is always going to be a weak link in any driveline if you pound on it hard enough. If you know what it is and continue to abuse it then it will break for sure.


I'm sure this will stir up all sorts of flames....LOL....but I had to say something. This thread was turning into a big "piling on" the diff issue and needed a contrary comment....to even things up and provide some new fodder for commentary. I'll duck now.......LOL

Dreamin
05-03-05, 06:55 PM
The problem is people count a 'whining' diff as a 'failed' diff... doing that you have a LOT of failures.

But if you count 'failed' diff as blown up diffs... there are <relatively> few of those.

And what's whing in the diffs? The "gears" right? Can only those be replaced with properly mfg'ed, hardened ones? Couple hundred $$$ right??

BeelzeBob
05-03-05, 06:58 PM
The problem is people count a 'whining' diff as a 'failed' diff... doing that you have a LOT of failures.

But if you count 'failed' diff as the diff blew up... there are <relatively> few of those.

And what's whing in the diffs? The gears? can only those be replaced with properly mfg'ed, hardened ones?




What do you mean ..."properly mfg'ed, hardened ones?"

The production gears are properly hardened and manufactured...and shot peened for strength.

Geno
05-03-05, 06:58 PM
I'm one of those with no rear end problems. A lttle whine but next to the x-pipe and maggie, it's negligible. As I have stated many times before I drive the car aggressively. The only time I have experienced wheel hop is accelerating with exuberence after the Maggie install. With that said, I know from 35 years of hard driving that wheel hop of that nature will tear a rear apart.

I just want the peace of mind knowing that the rear will survive those rare occasions when the hop happens. Because 90% of the miles on the "V" are for trips, I do not want to be stranded 1000 miles from home because the rear decided to go South.

I spent a lot of money on this car already, because I still think it's one hell of a car. If spending the amount of money DTE is estimating will give me a robust rear, then I'm going to put it in. The rest of the "V" world can second guess their car's ability to get them the next mile...I will not.:)

Dynotech Engineering
05-03-05, 07:05 PM
The production gears are properly hardened and manufactured...and shot peened for strength.

:histeric: :histeric: :histeric:

Not from what we've found and documented.....


Sorry, no offense...but that is REALLY funny.

Dreamin
05-03-05, 07:08 PM
What do you mean ..."properly mfg'ed, hardened ones?"

The production gears are properly hardened and manufactured...and shot peened for strength.

Ok, so what's whining and how do you fix just it?

I disagree that all whining issues are caused by bad break-in procedures... MANY people swear that they followed the break-in procedures / babied the car / etc and still end up with whine.

drewcruikshank
05-03-05, 07:51 PM
the whining could be caused by a number of things. The pinion depth, preload on the pinion bearing, if the ring gear is centered in the case relative to the pinion gear, and the torque on the carrier bearing bolts.
the meshing of the two gears in space, relative to where the axels come into the case is the important thing. this is very difficult for me to explain in words. There are so many axises that have to be right for a differential to work propwerly.
you need a dial indicator and lotsa time. the deeper you put the pinion gear into the case the less backlash or "play" you have the better.....to a point. The deeper you go puts more preload on the pinion bearing depending on what shims yu use and how heavy a crush collar or washer you use.
I dunno. this is gonna take forever and i'm drunk.
basically, it sounds to me like there is a quality control issue with Getrag/GM people setting up the rears. there should be +or- .003inch clearance one way or the other in how the gears mesh.
Whining is a sign that the gears are not aligned properly wheather it is on the accel, decel, or coast event in the driveline. A properly installed differential should not whine, period!
I think the cause of a lot of the failures is 18-30 year old kids putting diffs together using impact guns and "fire and forget" mentallity. Show me someone using a dial indicator and reference manual and I will show you a properly installed diff.
By the way, performance ring and pinion sets by richmond or whoever are SOFTER than normal. People who think heat treated or cryogenicly hardened ring gears or pinions gears are better, are stupid. HARDER=MORE BRITTLE. the softer/more elastic a metal the better it preforms in a diff. check the richmond website. the stage one, two, and three ring and pinion sets get softer as the performance demands increase.:yawn: :yawn: :yawn: :yawn: :yawn: :yawn:

Dynotech Engineering
05-03-05, 08:08 PM
People who think heat treated or cryogenicly hardened ring gears or pinions gears are better, are stupid.

We cryogenically treat ALL of our gear sets for the C5 Corvette applications with outstanding success in both durability and performance for a multitude of racing applications. Also, we've built nearly 580 of these Corvette differentials over the last 2 1/2 years to date and have had ZERO issues with any of our gear sets once we started cryogenically treating them.

I assume your statement above infers that we must be "stupid" then....????? Hmmmm, just an interesting observation. Have a nice day.....


Best Regards,
DTE

Geno
05-03-05, 08:14 PM
BTW the reason our diffs are failing is the Germans have a master plan to help out the Uber cars by selling GM junk diffs. This only makes sense since the Germans are known for their mechnical engineering prowness. They got to know the diff is garbage.

BTW, did I mention the French are good friends with the Germans.

:canttalk:

Dave's V
05-03-05, 08:19 PM
Right now I'm not willing to pay $3 to 4.5k for a new rear end when Cadillac should be doing it for free. Right now I'm not going to pay for a new rear end for 97,000 miles. I listen for the whine once in awhile (when I turn off the radio so I can hear the exhaust sound) but I'm not going to worry about it. I'm going to try to avoid wheel hop though and dumping the clutch at around 4k.

I think it is great that DTE is considering finding a fix for us. Once their product is proven to be good, I may reconsider.

For the people that posted they replaced the rear end 3+ times, why? Claim the lemon law and get a new V. Once it broke for the 3rd time, I would be demanding a new car.

urbanski
05-03-05, 08:26 PM
i'd buy it, with a maggie as the cherry on top :)

Dynotech Engineering
05-03-05, 08:27 PM
Right now I'm not willing to pay $3 to 4.5k for a new rear end when Cadillac should be doing it for free.

We concur completely, we just wish they would develop a better platform for us to start with that is much more suitable for the heavy vehicle application of the V-8 equipped Cadillac CTS-V. The combination of heavy weight with increased engine power output is very hard on driveline components, especially with a relatively low-range gear set as the 3.73.


Best Regards,
DTE

drewcruikshank
05-03-05, 08:50 PM
DTE, not calling you stupid. Just everyone thinks harder is better. Cryogenic treating does not necesserily make things harder, it just lines up the molecules in the metal making the whole conglomeration stronger. If I havent said it before, I will say it again, I am drunk. Sorry for the misunderstanding, peckerhead:lildevil:

BeelzeBob
05-03-05, 09:58 PM
:histeric: :histeric: :histeric:

Not from what we've found and documented.....


Sorry, no offense...but that is REALLY funny.


Offense taken. You put laughing faces on my post and then get crabby when people indicate your process might be questionable.....hmmm.... keep it civil least this blow up in YOUR face.


Exactly what metallurgical data do you have indicating that the gears are bad or whatever...??? Just curious if you checked the hardness or anything or is this just a guess on your part...??

Interesting observation on your part, BTW. I'll let Pratt and Miller know first thing tomorrow to get the gears out of the CTS-VR that spent the last two days lapping Mid Ohio as they may be "bad".... wonder why they didn't fail several races ago...???


BTW....reading your "documentation" you could have stopped at "it looks weak to us..." instead of simply repeating the same thing 4 or 5 times. There is no real analysis there...just your "educated" guess.

Dynotech Engineering
05-03-05, 10:07 PM
As we stated in that post before that you obviously ignored....."no offense", so interpret the post as you wish....

We NEVER guess at anything and our positive reputation over the years with well-designed driveline products through sound engineering is validation enough..... Nice try.


We wish you a nice day also. ;)


Best Regards,
DTE

b4z
05-03-05, 10:26 PM
DTE,

Possibly a stupid question here.
When you say the platform is weak are you talking about the body structure?
Or the mounting points on the body structure?
Is it the chassis/suspension parts that is flexing and not the structure?

I have driven many CTS's and own a SRX and have found the structural rigidity and lack of creaks to the best of any GM product I have owned.

I am not sure what specific area you are referring to.
I know that changes were made to the front of the vehicle to handle the torque.

Please clarify the areas that you find deficient.

BeelzeBob
05-03-05, 10:31 PM
I wish you a nice day, too, and I did read your post and took offense to it if you didn't understand me.

I would also like to see some substance behind the comments you made about the deficiencies of the gears and axle. If your laughing faces and comment to the effect of "that is really funny" have any substance behind it then tell me the hardness of the gears you didn't "guess" at, tell me the metallurgy that is so screwed up, tell me the dimensions that are off, tell me if the gear was shot peened or not which is what I indicated. Otherwise, you are GUESSING with your armchair analysis.

I was not talking about other products you may make and sell...I was talking about your comments about the CTS-V diff you "evaluated".

It reads to me like you really don't know much about it but had to make some negative comments to prove your superiority.

Vrocks
05-03-05, 10:45 PM
basically, it sounds to me like there is a quality control issue with Getrag/GM people setting up the rears. there should be +or- .003inch clearance one way or the other in how the gears mesh.
Whining is a sign that the gears are not aligned properly wheather it is on the accel, decel, or coast event in the driveline. A properly installed differential should not whine, period!
:yeah:

That's what I've been thinking for months now...... Someone might say I'm full of BS but I drive my V hard, and I haven't had a single problem yet. There isn't a single day that goes by where I'm not power shifting or sliding the car around. I also didn't make it to 500 miles before I got on it, ok, it was about 470 or so...

The car has about 14,000 miles on it, it's half way through a second set of tires, with 2 oil changes, and the OEM fluid is still in the rear (I was told it's good for about 50,000 miles).

Florian
05-03-05, 10:46 PM
ladies, ladies, ladies....get your panties out of a bunch and play nice.

Florian

1996deVille
05-03-05, 10:54 PM
My cousin had a 1966 GTO - 600+ bhp. He NEVER had problems with the diff, and that car would lift the front tiires off the ground in 1st and 2nd gear. He had the car for several years.

Nope, you've got BIG problems Caddy, and what's worse is that you won't do the right thing and fix this problem, or even admit to it. R & D should've caught this in testing...

Engineering left town on this one. For 50K this type of situation should not take place!

Dynotech Engineering
05-03-05, 11:05 PM
I wish you a nice day, too, and I did read your post and took offense to it if you didn't understand me. It reads to me like you really don't know much about it but had to make some negative comments to prove your superiority.


:histeric: :rolleyes2 :yawn: :boring: Incorrect- This is getting so old..... We meant no harm by any of our posts, but you obviously have something to prove by you taking such personal offense over a harmless smiley...

As we stated before twice now....take it as you wish, as we have nothing to prove to anyone, especially to gain your approval...

There's always one in every crowd and we have not the time or inclination to engage you in pointless banter and "chest beating" any longer. You seem to have *all* the answers regardless of your direct, first-hand experience, (or possibly lack there of- who knows) so I'll let you have that title. Congratulations!

We're done with you for the final time and have a nice day. Good luck in your endeavors..... :)


Best Regards,
DTE

drewcruikshank
05-03-05, 11:11 PM
That's what I've been thinking for months now...... Someone might say I'm full of BS but I drive my V hard, and I haven't had a single problem yet. There isn't a single day that goes by where I'm not power shifting or sliding the car around. I also didn't make it to 500 miles before I got on it, ok, it was about 470 or so...


Yeah, you must have gotten a good one. It seems like its the flip of a coin. You either get one that was put together right or not.

How do the dealerships replace them when you guys make a claim. Is it just new gear sets or the entire rear end assembly gets bolted in or what?

Florian
05-03-05, 11:13 PM
:yeah: GM took a huge dump on the diff and now claims that they dont smell it. I think we got hosed huge. :want:

Florian (I think I stepped in some GM/BM) :suspect:

Dynotech Engineering
05-03-05, 11:17 PM
We had a chance to speak with CTSVLS6 this evening after hours and we discussed the options posted here. He informed us that he'll post on the subject tomorrow. :)

We're going home now... 16.5 hours is enough fun for one day! :)


Best Regards,
DTE

CVP33
05-03-05, 11:33 PM
DTE,

Thanks for getting involved. We need more experts willing to share their findings with regard to equipment failures. The rear differential is under-engineered and barely capable of sustaining it's current horsepower levels. Not only are mod's out of the question, but wait until the '06's are produced. Unless they've modified the rear and detuned the LS2, our failures are merely the tip of the iceberg. 6.0 angry liters will make short work of the current set up.

DILLIGAF
05-03-05, 11:42 PM
DTE,stay with us here.I'm keeping my car forever!We understand what upgrade means.I will continue to beef up every part of this car as needed.A bullet proof diff out there for the buying ends the pissen contest.My mods are over 8k,not stoppen,i'm on a roll!

BeelzeBob
05-03-05, 11:47 PM
:histeric: :rolleyes2 :yawn: :boring: Incorrect- This is getting so old..... We meant no harm by any of our posts, but you obviously have something to prove by you taking such personal offense over a harmless smiley...

As we stated before twice now....take it as you wish, as we have nothing to prove to anyone, especially to gain your approval...

There's always one in every crowd and we have not the time or inclination to engage you in pointless banter and "chest beating" any longer. You seem to have *all* the answers regardless of your direct, first-hand experience, (or possibly lack there of- who knows) so I'll let you have that title. Congratulations!

We're done with you for the final time and have a nice day. Good luck in your endeavors..... :)


Best Regards,
DTE



No chest beating intended.

I said the gears are properly machined, the correct metallurgy and shot peened for extra strength.

You laughed at my comment and said it wasn't true.

I asked for your data, measurements, something to back up your statement. That is all.

You provide nothing, cop an attitude and sign off in a self rightous message about how tired YOU are with this. Hmmm.... Hopefully your lack of data to back up your BS is noticed by people other than me. You are, afterall, the one that brought up the subject of how weak the diff supposedly is...with nothing to back it up but your opinion.

I realize that without "inherent weaknesses" to "fix" the aftermarket suppliers like yourself would have nothing to do but it really isn't becoming to trash an OEM product like that. It may be possible to destroy the diff but it is not the weak kneed piece that you make it out to be. The fact that it can be used, virtually unmodified except for a cooler, in professional, high level competition indicates that it is a little more robust than you make out.

calicadi
05-04-05, 02:44 AM
Here's a question... what's in the Speed World Challenge V's? I emailed Pratt & Miller hoping to find out. No reply yet. May never get one. Maybe someone who reads these threads knows someone on the inside?

For the record, no problems with my diff. Only 3800 mi. on the odo, but about eight SCCA Solo 2 autocross runs.

StealthV
05-04-05, 02:54 AM
Here's a question... what's in the Speed World Challenge V's?

The CTS-VR uses the stock differential assembly (with a cooler).

My thoughts on this diff topic - proper preventative maintenance and don't waste money on a one-off proposed effort. A better investment would be the GM part number cooler kit for those really serious track guys (not me).

Playdrv4me
05-04-05, 03:30 AM
ladies, ladies, ladies....get your panties out of a bunch and play nice.

Florian

No shit man!! The rear end is crap for WHATEVER reason it may be. I certainly dont want to be the one standing by and telling V owners that they are basically lying and destroying the differentials on their own. I think all of you guys have provided more than sufficient evidence to prove this is not a "boy racer" problem isolated to those who may or may not abuse their vehicles. I for one think DTE has really stepped up to the plate here and the solutions they CAN offer are more than generous until GM can get its act together in my opinion.

drmustang
05-04-05, 10:00 AM
It appears that I just bought a 50K dollar car that will likely need some major service in the not so distant future and be repaired with parts that will repeat the failure. I can spend 3K or 4K myself and maybe solve the problem. This is absolutely, positively unacceptable.

ssmith100
05-04-05, 10:24 AM
I wasn't going to chime in on this sublect but I guess I will. There are a "few" of us out there that have modifications, drive there cars hard, and don't have "any" rear end problems. I do have wheel hop but I "don't" let the car keep hopping if I get into it. For all you new "V" owners out there that are getting discouraged because of the rear end, wait to see if you have a problem first before you judge the car. I personally love mine even with it's certain nuances.;)


Shane

CTSVLS6
05-04-05, 10:42 AM
Talked to Phil last nite and I have decieded when we return from vacation in June to let him have the car for how ever long it takes. It won't be a simple project and may require 1 to 5 months. He has a really good setup in mind that I know will hold up to the additional HP that I allready have plus more. He also said this kit will eliminate the wheel hop. I know I will have V withdraw but it will be worth it when it is done.

SBONES
05-04-05, 10:45 AM
I feel the same, I get up every morning pissed. I love the car. I think something isnt right. Why would gm build a half assed car. If the diff is the problem make it better. Then and only then will the v be the best. Then they really have bragging rights. Im in it to win it. I just hope somebody fixes this car. The car is to awsome to let something like a diff problem set it back. :helpless:

If we all know the truth about the week diff and its problems.( clunk and vibration ) Caddy could at least address this..But they will tell you its normal.:hmm: :rant2:

riverrat
05-04-05, 11:49 AM
Hey bbobynski I take it you do not believe that my rear blew after 300 normal miles. I guess itís OK for you to say I must be lying, crazy or what ever but you get all upset over smilies. I see you are a 4200 post Bonneville driving Caddy Connoisseur But Imí a 53 year old punk that must be out beating my CTS-v to death during the break-in period. Of course that would be because I never had any thing else to go fast with and could not control myself with a Z06 and a Lightning in the garage. The rear blew with no warning no leaks anything while driving south on I71 on the way to Kentucky Speedway to watch a Busch race with 70,000 others abusing their rears on the way.

As far as DTE and their Knowledge about rears Iím a believer with a $1700.00+ DTE/Getrag differential with severe duty output shaft and a $400 differential strut kit for my vette because guess what - you can break the stock one into pieces.

Lightning owners all cry that the rods are too weak and if you mod the motor too much you can kick the rods out. Solution - built short block. And bitch that Ford should have know and why do they have better rods in new Cobraís.

So if someone comes up with a fix and I was only hoping for a $3000 fix if itís more it Ďs more. And it is only something you do if you are modding or not willing to let Cadillac keep fixing/replace with upgrade in the future.

My replaced rear has been fine but I only have 3000 miles on my V - too many choices to drive but I still like it and will keep it for a long time. :histeric: :histeric: :histeric:

1996deVille
05-04-05, 11:50 AM
I have been considering the purchase of one of these cars and watching the V section of this forum has been very enlightening.

I may just go test drive one - it's raining in Seattle and I'd love to watch the face of the sales person when I dump the clutch on these streets today... and probably hop into the Ford lot nextdoor, smashing into a new Mustang!:histeric:

The problem is this IMHO. My engineering/R&D experience came by way of the Boeing model shop. Our job was to prove the design characteristic of the aircraft and interaction of all related components...

What's the first test the average person would run on the design of a SPORTS CAR with an already proven powerplant - we know from past experience where the N*'s advantages and disadvantages lie, so, to the running gear we go!

The acid test at Boeing for any new airframe is to destroy #1. And so we did. The "static" test pushes the limits of the design until we prove it breaks right where it should - as an example, the 757 wing structure broke at 22 feet above the centerline within 10 mil/sec of one another.

Someone needed to take CTS V #1 and do burnout after burnout until something broke, then go about fixing that problem... afterall, dumping the clutch is the only way to get to the advertised 0 - 60, right?

I'll bet this car needed to get to the showroom floor... and having the number of failed units we have on this forum alone, and this is only a small slice, is unacceptable in my case. I know engineering and R & D at Caddy will say otherwise, but, the proof is in the car on the showroom floor - and reading this forum shows we have unproven components waiting for purchase.

This is why GM is dropping market share. This will continue until R & D and engineering gets its act together. Stop making excuses and fix the problem!

b4z
05-04-05, 01:16 PM
GM used to have a certification process with the Turbohydramatic division where they made 200 1/4 mile passes. If the driveline lived then it was released to the public.

Maybe they still do this?

If they don't, maybe they should start up again.

BeelzeBob
05-04-05, 04:38 PM
If a rear end failed 300 miles after someone replaced it then it should be pretty obvious that it was either destroyed on purpose to prove a point or something was not put together correctly....likely the latter. I wasn't there so I cannot say but I do know that the rear end in the CTS-V is good for way more than 300 miles. I've put 500 miles on one in just one weekend taking people for rides, dumping the clutch, powershifting it constantly and basically abusing the car and it is still in the fleet months later doing the same duty. If your diff failed 300 miles after service then I would have to assume that it was not assembled correctly...not the diff's fault and 300 miles is certainly not a data point in the failures.

No, I don't get upset over smilies.... I get upset when someone takes a commment I make and puts in print that I am a lier by saying "that is really funny" in reference to my post. Read the post. I made the comment that the gear machining, metallurgy and shot peening was up to the task. No one is breaking gear teeth off or destroying the gear are they..??? DTE make the statement that this is funny based on "their measurements". I simply asked to see them or be provided with some information to back up their statement. They obviously have no information for they left in a snit. Keep that in mind when you spend money with them. If they cannot take someone questioning their analysis or statements then they must be pretty shallow. I can back up my comments about the gear based on the testing and quality control on the gears and the fact that the SAME gears live in the Speedvision CTS-VR's. Now I know DTE would have you believe that this is not possible and that you really need a cryogenically treated gear and such but the fact is that the production gears and diffs live under racing conditions in those cars.

I don't doubt that you can tear up a CTS-V diff. I also know that a knowlegeable driver can extract a LOT of performance out of the car time after time for many thousands of miles without hurting it. I have done it. None of the CTS-Vs in the fleet around here have torn up the diff and they are not driven by little old ladies, either....quite the opposite.

The drivelines still pass the "Woodward shedule" which uses a lot of clutch dumps and holeshots.


Seriously....could you explain to me what a " 4200 post Bonneville driving Caddy Connoisseur..." is. You have two years on me there, riverat, but I have no idea what a "4200 post Bonneville" is. The "Caddy Connoissewer" was not my idea but something that the forum puts up after enough posts I guess...LOL. If you are talking about the car that is mentioned in my posts...that was a 4.6 liter Northstar Bonneville GXP. I traded that for a 2005 SRX a long time ago.


As I indicated in my first post...I just wanted to add the bit about the CTS-VR experience with the diff. I didn't set out to be a poster child for flaming. Seems any comment to the contrary of this piling on of the CTS-V failure "ain't it awful" rant is not taken very well....so, have at it.

BTW....are there guidelines for what people expect out of a modified car or engine...?? Like, is it supposed to be able to take an extra 100 or 200 or 300 HP without blowing up or what.?? In my book, the engine and driveline is sold for use in the production car in the production configuration. If you modify it...it it YOUR responsibility, not the manufacturer's, to re-engineer whatever systems are necessary to handle the power. When did this change.? Since when should an engine or driveline be engineered to handle greater loads due to sticker/wider tires or an engine's lower end built to handle an extra 200 HP the owner might decide to throw at it with NO2 or something..?? I think that is the owner's responsibility. Just my thought's....interested in your viewpoint.

Did your Z06 diff break or did you just take preventative action because DTE told you it would..??

Besides, guys, if I didn't disagree with you this thread would have died a long time ago....so keep up the conversation. And lighten up. LOL

Geno
05-04-05, 09:40 PM
bbobynyski,



Hey, I guess us ďVĒ guys are serious about our rides, ďPassionĒ I think is the word. Those that had their diffs replaced want answers and not excuses or silence from the manufacturer. Finally as far as the post-jabbing goes, you give some and you get some (BTW Iím not giving any, just providing an observation).



Iím puzzled as many of us are about why some rears fail within miles while others are flogged relentlessly and nary a complaint. The rear diff should be like the LS6 motor. It should be stout enough to mod for a 50% increase in power without failing. Iím sure the vast majority of us have flailed the motor, but have you seen a single post about one blown to bits? That is an example of a well-engineered piece of metal.



As for the idea that someone didnít put the differential together properly, have you heard of ISO standards. Where manufacturers must produce a product according to established standards and must provide associated records . This is very big in Europe and Iíd bet my bottom dollar Getrag is an ISO certified company. I cannot image a production worker producing out of criteria or specification assemblies over a yearís period of time without at least one other person noticing.



The bottom line based on empirical and anecdotal evidence is the part is sub parÖ :helpless: periodÖ no excuses please.

BeelzeBob
05-04-05, 10:28 PM
All the suppliers that GM uses are ISO certified.

If a diff fails in 300 miles SOMETHING out of the ordinary had to be wrong. That is what I was trying to get across.

I, too, wonder why most diffs are fine and others fail quickly/repeatedly....?? It makes for an interesting debate.

Posting on this forum is like bbobynski against the world....LOL. I get a bit direct because I am constantly bombarded with negative comments. I'll accept the cross of being dumped on all the time for whatever is perceived as a GM problem or shortcoming as long as people are willing to accept the response. I don't try to BS anyone, just point out some obvious facts that might be overlooked or interpreted another way from the other viewpoint. If the info doesn't fit your preconceived notions of what is going on then it is not MY fault for mentioning it.

Trust me, between open forum comments and PM's I get my share of flames so I try to even it out by dishing it back.... LOL LOL LOL We are actually not that far apart on many viewpoints in reality. You learn over time that you can really learn a lot about a subject, however, by playing the devil's advocate....and/or arguing the opposite case because no one else will. It brings out a lot more info that way. I learn a lot here by that.

Vrocks
05-04-05, 10:36 PM
I have an idea...

We could take a CTS-V that hasn't experienced any rear diff problems, and compare it to one that does. We could check the alignment of every component in the rear, like the rear cradle, diff, driveshaft, axles, .... We could also compare the torque specs of the bolts holding the rear cradle and other rear chassis components.

Basically, we could compare everything that could influence the rear differential.

2004ctsv
05-04-05, 10:37 PM
If Getrag is ISO certified and they want to keep their certification, then write them a letter of non-conformance and they MUST respond.


ISO does not guarantee quality, only a paper trail and recording system.

I hadn't though of the ISO angle. If my diff dies, I plan to go that route. At least we can spread the pain a little.

Tony

Dreamin
05-04-05, 11:11 PM
ISO certification is crap... it's very easy to "fake it" and pass. I've never failed ISO cert... and i've worked for some really screwed up companies.

And as 2004ctsv posted, it does not guarantee quality... only that your procedures are documented and followed... Getrag would only have to prove that they are analysizing the diff failures, responding to GM in a timely fashion, etc.

They are probably documenting every case of whine as "improper" break in procedures... or improper install by GM... not our fault.

And i've never heard of a customer challenging an ISO cert... I dont think the Owner's manual says you are buying an "ISO certified" car.

Anyway it would be an entertaining path to take... their ISO cert is thru DQS in Germany:
http://www.dqs.de/servlet/ContentServer/DQSE/Page/DQSEKDBStart/c-Page/ContentServer?pagename=DQSE/Page/DQSEKDBErgebnisliste&KDBBranche=22&KDBBuchstabe=G

Dreamin
05-04-05, 11:20 PM
NHTSA is a better way to go... they can force GM to investigate/recall/etc.

http://www-odi.nhtsa.dot.gov/home.cfm

StealthV
05-04-05, 11:59 PM
Is everyone calling gear noise a "failure"? Actual catastrophic failures on this forum can be counted on one hand. Four or five catastrophic failures out of literally hundreds does not justify a complete redesign.

Seems most forum members are pro-Corsa because of the factory approval and anti-B&B as it may affect their warranty; yet are completely ready to toss their entire powertrain warranty out the window for some proposed effort that is far from being proven. Whatever GM, DTE or insert company x here may build in the future, I guarantee I could break it if I so chose to apply enough power and abuse.

IF there is ever a more "beefy" aftermarket solution, those V owners will now be breaking transmission internals such as input shafts. Don't think a diff with higher torque capacity is the one be-all end-all to infinite powertrain life. The next weakest link isn't very far away.

If everyone is calling the gear noise a "failure" to justify a redesign, pay me 50% of what DTE will charge you and I will guarantee your current diff will live and let you in on the secret to quiet gears.

wildwhl
05-05-05, 01:14 AM
Failure, at least to me, is defined as one of the following scenarios:

1) Catastrophic destruction which has not happened to me, and to my knowledge has either been case failure or half-shaft failure (mfg defects?) and some, but not all, have noted during hard driving (drag strip).
2) Enough metal during an oil change the dealer performed (~1/4 cup full) to assume catastrophic failure was near at hand and warrant replacement. Cause? If I had to guess - improper assembly (I can guarantee proper breakin was followed - I did so for the entire car's sake)
3) A locked diff (aka spool) that would not allow proper performance and made extreme noise during any slow speed turn with a lot of chatter, as well as created a potentially dangerous vehicle under normal operation. Cause? If I had to guess, the dealer's failure and refusal after replacement of the original diff last summer to add the limited slip additive. I believe I'm the only one that has reported this situation thus far.
4) Whine. Some may say whine is not a failure. I suggest that it is. If Cadillac did not feel that whine is a sign of premature wear or near failure, or at least that the unit wasn't performing as designed and/or desired and/or marketed, and elects to replace the unit under warranty - then in my mind that is Cadillac admitting that the unit is "failing to perform to expectation". If it wasn't, they wouldn't eat the cost of the differential replacements on the multiple platforms. It is FAILING to create satisfied, repeat buyers, that sell the product by word of mouth. It is FAILING to keep some of the current buyers in the vehicle for what should be several years of happy motoring. The LS6 power will keep you there, the interior and handling will, even the stereo and other creature comforts will, but the fear of differential failure is driving buyers and SOME current owners away. To me, this is a dismal FAILURE, and the ONLY dismal failure on this car (well, lack of MP3 capability, but that's a threadjack).

I agree that the "catastrophic failres" have been few and far between, at least as they have been reported on these forums. I would personally call the (previously) locked diff a catastrophic failure in the making - I'd have to guess that it would eventually "break", possibly causing bodily harm in the process.

Now for the good news and this is where I believe the true problem is in quality control and assembly procedures at Getrag, and I'm beginning to believe (knock on wood) that the diff might be up to the task if assembled correctly by the manufacturer. My current diff has had 2,000+ magnacharged miles. Prior to that it had less than 500 break in miles. I swapped the fluid at 750 miles to Royal Purple. I've recently decided to drive the car as intended by the designers and as I intended to when I bought it. Powershifts - yes. Near clutch dump and feathering (i.e. strong, hard launches) - yes. Is it whining? No. Is there wheel hop? Yes. Is it a magic diff that will last forever? Maybe. Do I want an aftermarket solution to make it bulletproof - maybe - but what I would personally prefer is elimination of wheel hop.

If THIS, my THIRD diff fails will it be Getrags fault, or the fault of the engineers at Cadillac? No, I don't think so. This time, it will be the unrelentless pursuit of horsepower...and if it fails will I then be one of the buyers who bails from the platform? Nope...I'll buy another one and install it. There has to be a weak link somewhere and unfortunately it appears in my situation it might be the diff (but I hope it is the clutch).

Now, should GM do something about it? I think so. I expect they are (remember, my emails to Getrag resulted in the admittance that a running change redesign part number, to what extent was not elluded to, would be used beginning in June of '05, IIRC). Should your diff fail now, I expect THAT is the diff you'll be getting as a replacement.

Just my .05 on a 2 cent topic.

Happy motoring, and, oh yeah, you should have seen the eyes bulge out of the heads at the Ford dealer today when I started the V back up and popped the hood for the curious :) Who needs a silly 2 seat GT anyway :sneaky:

Dave's V
05-05-05, 01:35 AM
I wonder how many V rear ends have failed or replaced due to whining. I remember there was a poll once on this subject and I believe it was close to 50/50 for the 75 or so people that responded. Since there are probably at least 6000 V owners, that is a poor sample. I don't think they replaced 3000 V rear ends.

Some V owners that don't frequent this site might not even know they have a problem (doubtful unless they are deaf). How many rear ends failed that were also modded and how many that were stock?

I agree with Stealth V that we have had very few failures but a lot of whiners. Mine was replaced at only 1700 miles but since I bought it with 661 miles I bet the dealer wheel hopped, clutch dumped, and "abrupt" throttle changes constantly.

I also question if the tires provide too much grip causing the rear end to be the weak link. Obviously the LS6, T56 and clutch could handle the power. What happens when the rear end is not the weakest link? Bad drive shafts, half shafts, CV joints, etc. I think if Cadillac took care of the wheel hop problem, the rear end problem would go away also.

Till the warranty is up, I'm going to be cautious about modding the car. Cadillac could easily say the "new" rear end caused the driveshaft or tranny to go bad. I rather not worry and let them fix it IF it breaks again.

Dynotech Engineering
05-05-05, 09:16 AM
The bottom line is this:

Most folks want to increase the performance of their car for whatever reason and they want to do so with the peace of mind in knowing that when they do, the drivetrain will support the newfound power comfortably for an extended amount of time in the future without worry. Whether one wants to cling to the fact that the Cadillac differential is adequete or not, that's thier perogative, but regardless of which way you choose to believe, the blatent, unavoidable fact is that the *current* CTS-V differential cannot and will not support the future of increased power output from this engine for HP street/drag use, even when an attempt is made to fortify it internally.

The very comical thing is that the very same folks that claim up and down that the current CTS-V differential is adequete, suitable, strong enough...whatever, are the very same one's who have never had one apart or who do not do this sort of professional performance upgrading for a living.... Unfortunataly, the internet breeds many "experts" because most folks can read at least and since they must have *read* something that seemed true..well, it MUST be.....

All of this is synicism from some folks about what we're trying to do to improve upon an overall poor design from the manufacturer is quite comical and typical I guess, because there will always be naysayers in any worthwhile endeavor, especially when they *really* don't understand the entire concept due to lack of practicle hands-on experience of what we're trying to do. (they'll never say that though)

About 2 3/4 years ago, we experienced the very *same* negative comments/synicism regarding the fortification of the C5 Corvette Differential and about how "we coudn't do it", "it won't work", "it's a bad idea", "THE STOCK DIFFERENTIAL IS FINE" :rolleyes2 :yawn: from many folks across the internet AND about how the 2-series differential was a weak P.O.S. that just *couldn't* be upgraded in any capacity to support HP Corvette applications...

Well...it sure was fun and satifying proving the naysayers wrong on both accounts, time and time again.... ;) Many of our differentials are living happy lives behind 9 and 10 second Corvettes that are absolutely brutalized on the drag strip and on the road course. We've developed a multitude of HD Corvette driveline components over the years that have been distributed and sold all over the world and our products do the talking on the track for us.

Ironically, the very same folks that were naysayers before/early in that venture are either now carrying our HD driveline products to sell for their customers, have purchased it for themselves, or they have attempted with limited success to copy our component design to market for themselves.

We intend to re-engineer the current Cadillac rear suspension/driveline design to a much stronger configuration that will support future performance enhancements *WITHOUT* gear set whining and wheel hop. We wouldn't be venturing into this if it was only a one-off project, as that certainly would NOT make viable financial sense. When we're complete with this endeavor, the solution will be holelistic in approach from the driveshaft to the halfshafts- complete. If you choose to purchase or not, that's ultimately your decision, but the odds are already against you if your using the *current* stock CTS-V differential for any type of performance use and the laws of probability will eventually catch up with you sooner or later- so good luck!

We know what we're doing and we've been there..... The best part is, is that the more we see folks claim that "we can't do it" and "it won't work", "we're foolish for trying it",....whatever- the more it drives DTE to strive above that to prove the naysayers wrong all over again as we've done in the past. To that- we thank them also! ;)

Necessity is the driver of invention.........

urbanski
05-05-05, 09:19 AM
The best part is, is that the more we see folks claim that "we can't do it" and "it won't work", we're foolish for trying it",....whatever- the more it drives DTE to strive above that to prove the naysayers wrong again as we've done in the past. To that- we thank them also! ;)

Necessity is the driver of invention.........
YOU CANT DO IT!!!!!!!!


;)



*reverse psychology

lasstss
05-05-05, 09:56 AM
This reminds me of the V8 in a Vega syndrome. What surprises me is that the V isnt an airplane. Usually the manufacturer designs is some margin when doing their engineering work. The V diff is on the 'edge'. Making a little noise wont make it fail. Its just plain too small for the car. Why they put a 6 cyl rear behind an ls-6 is beyond me. Having owned a 1968 eldorado with a 400 hydro sidewinder, I never broke the half shafts, and this was serious weight and serious torque. Perhaps the lightweight diet of this car caught up with the engineers and they thought the stabilitrack would save them.

Im up for the rear mod... just say when.

Florian
05-05-05, 10:04 AM
WW, Rick and Phil,

EXCELLENT POSTS! Very insightful, well thoughtout and concise... Nice to see educated posts! Thanks. :thumbsup:


Florian

CTSVLS6
05-05-05, 10:07 AM
AMEN.... If it weren't for all of us guys looking for better performance and trying to make are cars faster than the other guy, than we wouldn't have a need for shops like the ones listed on the left hand side of this page. Look how boreing life would be if we didn't have the need for SPEED, and I for one am really glad we have shops out there that take the time to develope the high performance parts that we need to make life more fun. I want a car that I can depend on if I have the need for speed and want to BEAT THE CUBES..

benjet
05-05-05, 01:08 PM
I wasn't going to get into this BUT...


I made the comment that the gear machining, metallurgy and shot peening was up to the task. No one is breaking gear teeth off or destroying the gear are they..???

I am pretty sure I/we have seen a few incidents of this, enough to say that it's not unheard of (while yet not the most common situation). In my own case there was a very high level of iron in the diff oil, and if the case is alum, then where's the iron coming from? And if the internals are chewing themselves up then a failure is eventually and unfortunately iminent (altho when is the real Q).

riverrat
05-05-05, 01:36 PM
I must clear-up something about my 300 mile failure. That was 300 miles off the showroom floor not after a repair. I have not had any problem with the replacement unit. Changed the rear lube about a week ago no metal just the usual on the plug. I do have a little noise but nothing I would go to the dealer over, more than likely it is from the BRM kit and pinion brace I installed. Also only 3000 miles total on my V.

Vette DTS rear and strut kit is a gear ratio change and preventative move for future additional HP. What I am trying to say about vette vs CTS-V is that more than a few Z06's (as Phil will attest) have blow the rear and trans along with it - that what the strut kit is about - due to flex of the trans axle. So I donít think it is out of the norm for modded cars to look to upgrade. I do think the failure rate for stock Vs is unacceptable.

2005V
08-01-05, 03:14 PM
We intend to re-engineer the current Cadillac rear suspension/driveline design to a much stronger configuration that will support future performance enhancements *WITHOUT* gear set whining and wheel hop.

I think its time to revive this thread. Does anyone know where DTE is on this? I thought that someone here had agreed to be the test mule for this. Any updates?

Nick

wildwhl
08-01-05, 03:20 PM
This thread has bad karma built in.

I'd suggest a new thread to gain new interest.

Dynotech Engineering
08-01-05, 03:41 PM
Here is a previous response we posted a while back regarding this project, so we'll post it here again for those that missed it. We also concur with wildwhl that this thread is a hornet's nest and should probably be retired. :)

***COPY***
The HD Cad. CTS-V differential project was side lined for the time being. CTSVLS6 decided that he didn't want to give his car up for the time it would take to complete a new venture such as this, right in the middle of the summer driving season. (we don't blame him) With that said, if/when we do any sort of thing like this, a major portion of our decision to move forward will pivot on CTSVLS6's desire to offer up his car for protoyping AND after we consider the results of a feasibility study to see if a product offered like this would be profitable for us in the long-term.

One *REALLY* can't imagine just what kind of R&D time and capital it takes to move into a major driveline re-design venture such as this from it's inception to the final product offered to the public, especially for a limited production, low production-volume vehicle as the Cad. CTS-V. We've been there before many times when designing/engineering other HP products for relatively small niche' of the C5 Corvette and KNOW from experience. Often times it takes quite a number of a given product sold before we even come close to breaking even and if the numbers aren't there, then we're not stepping into something this complex just to "see if we can do it". That's just not wise business sense and there is no sense in doing something half-hearted if it cannot be done right the first time....

This is especially true if GM does come out with a better differential than what they have now that's retrofittable to older cars, which would halt sales significantly of other more expensive aftermarket parts, albeit them being better quality however.... That's just the way it falls in the aftermarket..

We're not closed to the idea of continuing with this venture and we certainly have the engineering ability and desire to do so, but if the company as a whole does not experence financial growth from the endeavor in the long-term, well, then...what we want to do as engineeres' here "just to see if we can do it" and what we can, or are willing to do as a company, for the benefit of the company, are two completely different things..

c5racr1
08-01-05, 08:22 PM
build a kit to retro fit a c4 dana 44 or dana 36

BliTzer
08-02-05, 04:22 AM
Hell with it.. Ive gone this far with my V, & maggie im like wldwhl i dont drive like i should at times either. When i do get on it, and i have very hard but not dropping clutch, so far so good.. i have inspected it numerous times.
so hell with it, im going to try to get vette diff installed/fab whatever..
I spent 6k on maggie & dyno, another 4800 on bore crank/cam combo, & numerous other mods.. so might as well take it to the limit.

Im going to make a video of my V, romping on it.. maybe do a 3 times n a row thing. I can put camera inside so it will show times on run.. maybe do a 1/8 & 1/4 mile run..& run the hell out of it.. If it explodes, well, i guess we have a video to watch..

then if i can find someone here in Phoenix to do this diff changover, i will make another video, do same runs, check times again.. check all issues in fact..

Sound good?

later blitzer..

akm2k5
08-02-05, 05:38 AM
Thats the spirit! :) Goodluck..

Hell with it.. Ive gone this far with my V, & maggie im like wldwhl i dont drive like i should at times either. When i do get on it, and i have very hard but not dropping clutch, so far so good.. i have inspected it numerous times.
so hell with it, im going to try to get vette diff installed/fab whatever..
I spent 6k on maggie & dyno, another 4800 on bore crank/cam combo, & numerous other mods.. so might as well take it to the limit.

Im going to make a video of my V, romping on it.. maybe do a 3 times n a row thing. I can put camera inside so it will show times on run.. maybe do a 1/8 & 1/4 mile run..& run the hell out of it.. If it explodes, well, i guess we have a video to watch..

then if i can find someone here in Phoenix to do this diff changover, i will make another video, do same runs, check times again.. check all issues in fact..

Sound good?

later blitzer..

urbanski
08-02-05, 08:41 AM
LOL BliTzer i like your attitude :cheers:

2005V
08-02-05, 10:14 AM
Hell with it.. Ive gone this far with my V, & maggie im like wldwhl i dont drive like i should at times either. When i do get on it, and i have very hard but not dropping clutch, so far so good.. i have inspected it numerous times.
so hell with it, im going to try to get vette diff installed/fab whatever..
I spent 6k on maggie & dyno, another 4800 on bore crank/cam combo, & numerous other mods.. so might as well take it to the limit.

Im going to make a video of my V, romping on it.. maybe do a 3 times n a row thing. I can put camera inside so it will show times on run.. maybe do a 1/8 & 1/4 mile run..& run the hell out of it.. If it explodes, well, i guess we have a video to watch..

then if i can find someone here in Phoenix to do this diff changover, i will make another video, do same runs, check times again.. check all issues in fact..

Sound good?

later blitzer..

Sounds good to me Blitz! I didn't mean to stir up a hornet's nest by bringing this thread back to life and I respect DTE's decision whatever they chose to do. I just love this car and I will pay whatever it takes within reason to eliminate the weak link in the drivetrain. Until then, I will continue to drive it hard like it was intended to be driven.

Nick

BliTzer
08-02-05, 05:22 PM
Hey, its all good.. Im tired of feeding it a nipple everyonce & awhile. So today, im fixing to leave in a few ninutes & go around to different shops, i have list of potential garages that are good, that might do it or who knows have done it already, that would be even better.

I will let you know as soon as i found out more.

Ubanski! you just want to see the video explosion.lol ;P
Edit: I also going by a few camaera shops to find in car mount for cam.
later..

BliTzer
08-03-05, 03:21 AM
Ok i found car mount for video camera.. its pretty cool.. its real stable as well.. Let me get rear spoiler on, i bought xtra trunk lid, so we will switch it out, and i can always convert back to stock in no time. If i sell, and they dont want it, they will have option as well..

I should be completed with that, & rest of gauges by end of week.. i hope.
I got delayed due to hurricane that hit right outside of Pensacola again, uhg.. so i had to meet FEMA & Insurance companies to get that staight. I have some condos in Destin, FL that i keep rented out, and 7 timeshare units as well. so thats xtra income that i keep flowing..

With all that in mind, i hope i can get back on track & get things finally completed.

So maybe, week from this friday, i take it down to Chandler at track & run it on fri or sat nights...and then do the after shots once i find someone to convert diff.
I was all over place today, 12 different garages.. all said nope, they do not want no part of it, fear to warranty it blah balh..
So tomorrow i have 3 appointments to meet to see if they will.
Also, Arizona Pro Dyno chip might do it,, they do alot of mods & alot of works with vettes, so it looks promising.

So get ready to Rumbblle, via video.. ;P

later blitzer..

PS: digtalpimp & rest of AZ guys.. want to meet at track? if so let me know..

Dynotech Engineering
08-03-05, 09:54 AM
Here's a copy of the response we made to the other differential thread, since both are running at the same time.

Here is something to consider.. If you can wait just a bit until the '06 CTS-V are relased, you may find your stronger differential re-design right under the 2006 model year chassis AND it's likely it can be made to retro-fit to the 2004-'05 model year vehicles with less overall cost/effort than what it would be with a completly different aftermarket re-design. In speaking with some folks in "the know", we've been led to belive that, so time will tell to confirm if all you folks can wait just a bit longer.

If that is in fact the case and the '06 differential is built more heavily from the start with a better foundation platform, than we WILL more than likely go into the differential and strengthen it like we've already successfully done with the C5 Corvette for the last 2 1/2 years. :)

BliTzer
08-03-05, 11:15 PM
Ok, understoond DTE. I will wait, or until it or if it blows apart. If it goes im not going to waste precious time reinstalling pos. We can all make money, thats the easy part, getting back or wasted time, no fix for that..

So i will do that, ok.. ;)



thanx dte..

later blitzer