: new gen 4 diff, which oil? also broken out of the box ugh



bneal1022
07-05-10, 11:56 PM
hi guys..
very excited I made enough $ buying, refurb, and selling V parts and more to buy my own new gen 4 diff as mine is dying (those at v-day4 know) :thumbsup:. Got it home from GM dealer, they loaded it in my wifes car. I lifed it out of box and..... tink a tink tink. aluminum pieces on the garage floor. The fins in the case are all broken. Apparently it was dropped before I got it. :want::suspect::mad:

Needless to say I held the check until they get a new one for me.. I will fight that battle tomorrow.

So, I (will) have a new gen 4 diff for $1498. I know the factory oil is Mobil 75W-90 with the GM friction additive. I replaced my original diff oil with Royal Purple 75W-90 Max-Gear which already has the additive in it a year ago. It did quiet my diff for about 6 months.

So with a new new diff, what oil does the group reccommend? I was planning on just starting out with RP. thoughts?

I will be transferring my CS gray bushing... oh BTW, the new diff does not include a vent... anything I need to know about a vent? I saw posts about a vent or vent leaking issue in the past. input? :confused:

darkman
07-06-10, 08:36 AM
The GM fluid is not Mobil1 75w-90. The GM fluid, Part #89021677, is the only commercially available fluid that meets GM specification 9986115, which requires a specific high temperature endurance test not required to meet the API-GL-5 standard. Technically, the use of other fluids would not maintain the original warranty. For obvious reasons, the warranty issue is moot and was never enforced because even when a differential failed the dealer had no practical way (or incentive) to tell what fluid was being used in the failed unit.

I personally still use the GM fluid because I am stubborn, but it is expensive.

If I were to switch fluids it would be to Amsoil Severe Gear.

AAIIIC
07-06-10, 12:03 PM
I'm using Amsoil. Can't say it's any better or worse than anything else.

lilgCTS-V
07-06-10, 04:41 PM
gen 4 ???

bneal1022
07-06-10, 10:03 PM
gen 4 ???

it depends on what you call a "gen" or part number. there have been at least 4 different part numbers for our diff. I actually have a 1308 in my car and according to several others, these never made it far in the field.

Gen. 1st---- 10361308
2nd---- 12378261
3rd----- 15793756
4th----- 25873498

Ok so that is 2 votes for the amsoil, zero for RP, and 1 for OEM. I just wanna do whats right for my new diff right out of the gate.

darkman...
is this the fluid? it is a 75w-90 synthetic. does this need the additive or not?
http://paceperformance.com/index.asp?PageAction=VIEWPROD&ProdID=21329

or i guess i could use the amsoil.

the RP meets API GL-5
http://www.royalpurple.com/gear-oil.html

JDB
07-06-10, 10:22 PM
I recently had mine replaced under CPO warranty with gen 4 and the dealer only used the new GM fluid, no additive. They said the additive was a "fix" to use with the older diffs, which obviously didn't work.

verywhitedevil
07-07-10, 12:54 AM
i use Royal Purp 75/140 w/ additive. no issues.

ewill3rd
07-07-10, 09:11 AM
JDB, what did you just say?
The additive is required from the factory.
Stay away from that dealer or educate them.... :cookoo:

thebigjimsho
07-07-10, 09:53 AM
The GM fluid is not Mobil1 75w-90. The GM fluid, Part #89021677, is the only commercially available fluid that meets GM specification 9986115, which requires a specific high temperature endurance test not required to meet the API-GL-5 standard. Technically, the use of other fluids would not maintain the original warranty. For obvious reasons, the warranty issue is moot and was never enforced because even when a differential failed the dealer had no practical way (or incentive) to tell what fluid was being used in the failed unit.

I personally still use the GM fluid because I am stubborn, but it is expensive.

If I were to switch fluids it would be to Amsoil Severe Gear.


I'm using Amsoil. Can't say it's any better or worse than anything else.
Of all fluids put in this car, a quality fluid anywhere is fine. But for the diff, I'd look for any little benefit I can. I didn't get Amsoil Severe Gear in my '04 before my accident. But I used it in my '09.

Now, is it any better? Not sure. But some guys have gotten diff temp warnings on the track. At Summit Point, I did not and you remember how oppressive it was that day? No issues. So I'm inclined to keep using it...

darkman
07-07-10, 10:56 AM
[quote=bneal1022;2295777]
darkman...
is this the fluid? it is a 75w-90 synthetic. does this need the additive or not?
http://paceperformance.com/index.asp?PageAction=VIEWPROD&ProdID=21329

Here is the additive.

http://paceperformance.com/index.asp?PageAction=VIEWPROD&ProdID=29478

The Royal Purple has not done well in compartive tests. We have had more postive feedback on Amsoil Severe Gear than any other single product, particularly from those who track the car.

nmaier2201
07-07-10, 07:33 PM
If I were to switch fluids it would be to Amsoil Severe Gear.

+1 I've been running severe gear and it's been great to me*.









* your experience may vary

bneal1022
07-07-10, 08:48 PM
alright.. which amsoil weight and with w/o GM additive?

ewill
from the dealer exactly what part numbers do I need? fluid and additive? It even requires additive with 89021677

ewill3rd
07-07-10, 11:00 PM
The friction modifier is the same part number we have used for years and years.
From the CTS-V owner's manual you need:


SAE 75W-90 Synthetic Axle Lubricant (GM Part No. U.S. 12378261, in Canada 10953455) meeting GM Specification 9986115. With a complete drain and refill add 4 ounces (118 ml) of Limited-Slip Axle Lubricant Additive (GM Part No. U.S. 1052358, in Canada 992694) where required. See Rear Axle


I think the 8261 number changes to the 1677 in the catalog and they just never updated the manual. ;)
The issue is most Cadillac dealers aren't used to the limited slip differential and they really don't understand that the V has one and that it requires the additive even though it doesn't have the G80 RPO on the build sheet. It has a G80 diff, but it is part of the V package and not listed as an option on the label because of that.

lollygagger8
07-08-10, 10:37 AM
I use Redline and love it. I even stepped up to half 75w90 and half 75w140 and it quieted down the whine substansially. Plus it has LSD modifier built in.

I have tried the GM stuff, and it was noisy off the get go, didn't smell like grapes (lol), and was more expensive after buying the LSD modifier bottle. Booooo all around.

If you have to add LSD modifier, always put it in first. THEN, put the gear oil in. That way you make sure you get the entire bottle of modifier in there.

As far as the vent goes.... Use a socket that just fits over the vent but touches the ridge of it, and tap it into the diff with a hammer.

maxspeed96ct
07-08-10, 03:31 PM
Congrates on the new diff! I hope to get a gen 4 someday aswell .

were did you get it for that sweet price ?

bneal1022
07-08-10, 05:23 PM
max - I PM you

wow, surprised to see the variety (lets call it variation) in fluids used. In the quality world variation is the enemy :hide:

still stumped on which weight amsoil? 75w-90?

my original did quiet a little with the RP, but i see nobody else using it. That should be a hint I guess. Like most, just want the BEST fluid for the diff right out the gate is a brand new unit. I may track once a year.

AG'S-V
07-08-10, 06:16 PM
I broke mine in with the GM stuff at a track day actually.

Swapped in RP 75W-90 after, I have a smidge of whine...but nothing compared to the way my 1st gen sounded...

thebigjimsho
07-09-10, 01:19 AM
max - I PM you

wow, surprised to see the variety (lets call it variation) in fluids used. In the quality world variation is the enemy :hide:

still stumped on which weight amsoil? 75w-90?

my original did quiet a little with the RP, but i see nobody else using it. That should be a hint I guess. Like most, just want the BEST fluid for the diff right out the gate is a brand new unit. I may track once a year.
Yes, 75W-90...

lollygagger8
07-09-10, 10:19 AM
Indeed.

PISNUOFF
07-09-10, 10:51 AM
Hmmmmmmmm.





















LOL.

I have the 75W110 Severe Gear in there now and it's a little quieter. Mine screams like a pig at 45-50 mph with the GM stuff, I can hear it loud and clear over the B&B exhaust. I'm moving up to the 75W140 next time.

darkman
07-09-10, 11:08 AM
It seems to me that one possible contributing factor to the gear whine is wear and tear on the ring and pinion gears when cold. I say this because the differential lubrication system has no "oil pressure" and relies solely on splash lubrication. So, if you start running the car hard before the differential gets up to its operating temperature wear could be accelerated as compared with operation once it is warmed up. I use the transmission temp gauge as an indicator that the drive line is warmed up because it takes much longer than bringing the motor up to operating temperature.

The point of all this is that if you choose to go with higher viscosity fluids, I would advise even more warm up time before engaging in hard acceleration.

Of course this is just a theory.

AG'S-V
07-09-10, 11:18 AM
Makes sense...

bneal1022
07-10-10, 12:52 AM
Of course this is just a theory.

remember, you can only disprove a theory. Proving a theory makes it a law.

serik
07-10-10, 05:43 AM
redline shockproof light gear oil havnt put it in my v yet but used it in my other cars and its best oil out there for diffs and trannies

bneal1022
07-10-10, 11:17 AM
so you would use the "light" shockproof which is like a 75w140 over the 75w140 gear oil? whats the difference? betweent he shockproof and the gear oil? would you still use additive? why so thick? should it not be 75w90? why have you not put into V?

i'm about to close my eyes and point at a fluid.... just want a chatter & whine free new diff with proper protection for 2 day/week driving in PA with 1 track day a year.

bneal1022
07-10-10, 06:01 PM
what about the Redline lightweight shockproof gear lube + additive? It is designed for splash lube as our diffs are, and has a heavier weight (as i see many above 75w90 into the 140 range). will still get additive to add as required... thoughts?

http://www.redlineoil.com/product.aspx?pid=43&pcid=8

maxspeed96ct
07-11-10, 06:26 PM
Bleal you seems to have some good differential knowledge .

Im finding alot of 06-07 diffs for sale for some sweet prices (157*** part number)

Would you suggest upgrading to one of these ? or should I not bother and wait till I can get a Gen 4

TroyFleming
07-11-10, 06:36 PM
Bleal you seems to have some good differential knowledge .

Im finding alot of 06-07 diffs for sale for some sweet prices (157*** part number)

Would you suggest upgrading to one of these ? or should I not bother and wait till I can get a Gen 4

Unlikely you find a a used GEN 4 for cheap, so it's probably dealership which will take you to cleaners. Now the 157 part number diffs are all over Ebay for cheap, but remember if it ain't 3.73 gearing it's not from the CTS-V, there are cheap 157, but with different gearing. When you find the 3.73 diffs they range from $800-1000, the odd few slip through the cracks on ebay for $550-650 price range.

I have a updated GEN 3 and axles collecting dust in my shop if anybody needs one.

maxspeed96ct
07-11-10, 06:59 PM
Unlikely you find a a used GEN 4 for cheap, so it's probably dealership which will take you to cleaners. Now the 157 part number diffs are all over Ebay for cheap, but remember if it ain't 3.73 gearing it's not from the CTS-V, there are cheap 157, but with different gearing. When you find the 3.73 diffs they range from $800-1000, the odd few slip through the cracks on ebay for $550-650 price range.

I have a updated GEN 3 and axles collecting dust in my shop if anybody needs one.

junk yards around the us, cleveland pick a park and ebay always have 157*** 3.73 limited slip V diffs for cheap (~$500, seen a few for even less).

Im running a gen 1 diff, And id like to one day upgrade but im tryin to decide whether to upgrade to the 157**** or just keep saving and buy a new gen 4

bneal1022
07-11-10, 07:00 PM
max.. the part numbers i gave earlier are all 3.73 the key to the final diff solution is the robust prop shaft boss on the front of the diff. The case of the gen 4 is meatier and better structurally. I can't explain the "diff" between the diffs (get it, diff joke), until the latest. If interested I can likey get you the same offer for a new gen 4 i got on mine. Just talked about it with my friend at the parts counter last night. PM me if interested.

I woudl reccommend just finding a way to go for it all and get a 4th gen. I will be installing it with my newer Gforce passenger side econo axle and DMH cutouts...

i think I will use the redline lightweight shockproof gear oil with 1oz of additive as needed. unless others object (i'm listenting)
http://www.redlineoil.com/product.aspx?pid=43&pcid=8

TroyFleming
07-11-10, 07:43 PM
junk yards around the us, cleveland pick a park and ebay always have 157*** 3.73 limited slip V diffs for cheap (~$500, seen a few for even less).

Im running a gen 1 diff, And id like to one day upgrade but im tryin to decide whether to upgrade to the 157**** or just keep saving and buy a new gen 4


Cleveland Pick a part has them, but when they sell them cheap they end up raping you on shipping. Checkout all there listings and you will notice the wide range of estimated prices. If a part sell's at low end, they charge the highest shipping, if higher selling price, they work with you on shipping. Personally I would just save and go new with the GEN 4 if you have the money and plan to really get on differential. If you are not abusive the GEN 3 will last forever and probably 1/3 the cost.

bneal1022
07-11-10, 09:58 PM
how about a break in period? How long (in miles) should i go with new fluid and 4oz additive to reduce temps for break in, then change out to fresh fluid and additive only as needed? should i use a different weight oil during break in? should i take a long run for a while or short regular use for break in?

darkman
07-11-10, 10:12 PM
how about a break in period? How long (in miles) should i go with new fluid and 4oz additive to reduce temps for break in, then change out to fresh fluid and additive only as needed? should i use a different weight oil during break in? should i take a long run for a while or short regular use for break in?

The break-in procedure that I used at the recomendation of a Service Manager was as follows:

For the first 500 miles-
1. Avoid constant differential rpm - that is don't go on a long trip on the interstate and try to vary speeds as much as traffic allows.
2. Heat cycling - Avoid driving more than 30 minutes without a cool off period.
3. Avoid full throttle unless you are about to let it cool down for awhile.
4. Change the fluid at or about 500 miles.

bneal1022
07-11-10, 10:27 PM
thanks darkman !! the info below is from redline's page about diff break in. sounds like i will use 75w90 or stepped to 75w140 with the additive as specified below with your notes above.. thoughts?



MORE TECHNICAL INFORMATION


Limited-slip or Positraction units use plates or clutches to provide the proper amount of lock-up to the differential. Slippery lubricants are required to prevent chatter, but too much slipperiness causes excess wheel spin, reducing traction.
For perfect traction, use Red Line 75W90NS and add the Red Line Limited-Slip Differential Friction-Modifier / Break-In Additive until the chatter disappears.

Satisfies performance requirements of GM 1052358, Ford M2C118-A, 19B546-MA, Chrysler 4318060 and most imports.

Recommended Dosage:
Use 4% for prevention of limited slip chatter in broken-in units (typical one 4 oz. bottle) or 4 to 8% for the break-in of new differentials.

Red Line Limited-Slip Differential Friction-Modifier / Break-In Additive will significantly reduce the friction during break-in of differentials. High temperatures encountered in break-in
can destroy the hardening of the gear teeth causing rapid wear of the softened gears. This additive can reduce the break-in temperatures by as much as 50°F, improving break-in conditions. Compatible with petroleum or synthetic gear oils. Red Line Gear Oils already contain this additive (except the NS).

In non limited-slip racing differentials and quick change units using the Red Line ShockProof Gear Oils an additional 3 to 6% Red Line Limited-Slip Differential Friction-Modifier / Break-In Additive is recommended.

darkman
07-11-10, 10:38 PM
Sounds like you've got a plan - the theme seems to be to avoid sustained heat during break which makes sense because the ring and pinion gears have to wear in and that means friction. The Redline additive is based on the same theme.

kirchbed
07-15-10, 07:39 PM
Tangential post here:

Dropped the V off at Lindsay on Monday to replace leaky water pump & asked Alex (service writer) to see if my warranty provider would cover a diff replacement. Total wildcard request... I have the standard 45-65mph whine, but that's it. Frankly, I wasn't sure how extensive my driveline coverage was and at the least the request would let me know.

I had asked Bill (senior tech) there to evaluate my diff when I took it in for the VDay IV check-up early in June and he wrote up that it indeed had the whine that was likely caused by the diff housing deformation and the the std fix by Cadillac is full diff replacement.

Yesterday the warranty provider sent out an inspector, Bill gave him the 'let me tell you 'bout CTS-V diff' speech and, for the cost of my $250 deductible for a water pump replacement, I'm getting $3k+ parts and labor that includes a new current generation differential. They guy didn't even drive the car!

I feel like I just got a hole in one. I'd be buying you all drinks right now if you were in the area!

I heart Bill and Lindsay Cadillac!

Quadruple smily icons to follow:


:ride::banana::dance::banana:

kirchbed
07-15-10, 07:47 PM
New-found appreciation for Brandon and D'man's diff break-in strategies.

I will be applying this to my situation. Thanks guys!!!

JNR
07-15-10, 08:00 PM
Is there somewhere on the housing the part number is visible?

I have an 07 and the previous owner was telling me that the service dept. upgraded the rear, but I was under the impression the 06-07's already had upgraded diffs and halfshaft(s) was it? I want to see if I can get the report of services done on the car, if at all possible (guy from the GTO boards used to do this...was a GM-IVS-something report.

Thankfully, mine is super quiet (no whine whatsoever), but want to know if he's full of crap and/or what I have in there. i plan to change the fluid soon and picked up some Mobil 1, but not so sure if I want to chance the equa-torque additive they sell or get the dealer stuff...My GTO was fine with it, but a Jeep (had electronic lockers) did not like it one bit (the additive)...I've always had good luck with M1, fwiw...

ewill3rd
07-15-10, 10:48 PM
kirch,

I have you slated for the install tomorrow (Friday) and I plan to have it done.
I am waiting on a part for an XLR and I have a big estimate to put together for some impact damage on another but I should be able to get it on the lift pretty early and me and my helper should be able to knock it out pretty quickly.
If I can keep the advisors from loading me down early I should have you ready to go by late tomorrow.
I will try to have John call you as soon as it is done.

I'm glad we could help, the last extended warranty would only pay for a salvage unit like I told you earlier today.
I am surprised they are paying for it but I think what I told him about the updated unit helped.
I think they will soon realize the futility of dealing with a pre-08 unit.

bneal1022
07-15-10, 11:19 PM
Kirch, nice work with the diff. I only had 1 month left on my warranty when I got my v last year. Oh well, new diffs for all! I just got my 2nd new gen 4 unit last weekend and it was not damaged in transit. Got a new vent and tube if I have a vent leak, and just got done assembling my new Gforce econo axle. And cutouts arrive this weekend. It is shaping up to be another big install day shortly. I will break in with amsoil 75W-110 with 4% redline breakin additive. Drain as darkman indicated then refil with new 75W-110 and only add additive as chatter occurs.

kirchbed
07-16-10, 09:01 AM
kirch,
I'm glad we could help, the last extended warranty would only pay for a salvage unit like I told you earlier today.
I am surprised they are paying for it but I think what I told him about the updated unit helped.

What you were able to convey to him is the reason I'm getting a new diff!


... just got done assembling my new Gforce econo axle....

I wish this all had been a little more planned out... I would have ordered a Gforce axle and had it installed w/ the new diff since it was going to be all apart anyway.

kirchbed
07-16-10, 08:40 PM
Just picked up the car from Lindsay... no whine + no clunk = :cloud9:

Thanks again Bill!

ewill3rd
07-16-10, 10:26 PM
No prob Kirch, glad to help.

Hope you got to smile a bit on the way home ;)

I usually only remove the left axle to install the diff so it wasn't all apart.
If you get axles try to get the complete ones.
I have had boot issues on the other kits I have installed before.

bneal1022
07-17-10, 11:40 AM
No prob Kirch, glad to help.

Hope you got to smile a bit on the way home ;)

I usually only remove the left axle to install the diff so it wasn't all apart.
If you get axles try to get the complete ones.
I have had boot issues on the other kits I have installed before.

2nd that on the boot kits that came with the shaft... I'm not a fan of the replacements. one almost keeps popping off. I may get originals.

ewill3rd
07-17-10, 01:52 PM
Ooops, I mean the right axle, not the left... sorry.

JDB
07-18-10, 05:36 PM
JDB, what did you just say?
The additive is required from the factory.
Stay away from that dealer or educate them.... :cookoo:

That's what I thought (from reading this forum), but they said that they checked and it was not required to be put into the new diffs.

Is there a new GM fluid? PN? Someone earlier posted GM fluid, Part #89021677. That's the # on my invoice. They seem to think that this fluid works fine in the gen 4 diff.

Is there an 800 number Cadillac? ...because I want a 100% answer.

http://www.cadillac.com/pages/mds/helpcenter/contactUs.do ?

I'll be calling on Monday.

ewill3rd
07-19-10, 08:02 AM
The new diff is structurally different but it is still a limited slip.
That dealer doesn't know what in the world they are talking about.
The specifications I posted somewhere apply to replacement diffs as well.
It won't really do any short term damage but they need to get the modifier in there or the clutch packs are going to start grinding and making you nuts.
That is the right fluid, but they have to add 4 oz. of the friction modifier.

CadzillaTN
07-19-10, 12:44 PM
i got a new (what i assume is a new gen 4, i have not seen paperwork yet) diff friday. ive noticed that it sings a bit... that is, with the radio down and listening closely... seems worst in 4th on light decel around 40-50..other gears not as much noise if any at all.

should a new diff be whisper quiet or will all of these have 'some' noise? i recall the gen3 replacement i got in 08 being quieter than this.

im not worried about it breaking, just that perhaps the correct fluids were not added up front. i want to preserve this thing...

the car has not been driven hard at all since install and i dont plan on romping it for weeks.....this is going to be VERY hard not to do considering i had the cs grey mounts installed at the same time......

darkman
07-19-10, 12:59 PM
i got a new (what i assume is a new gen 4, i have not seen paperwork yet) diff friday. ive noticed that it sings a bit... that is, with the radio down and listening closely... seems worst in 4th on light decel around 40-50..other gears not as much noise if any at all.

should a new diff be whisper quiet or will all of these have 'some' noise? i recall the gen3 replacement i got in 08 being quieter than this.

im not worried about it breaking, just that perhaps the correct fluids were not added up front. i want to preserve this thing...

the car has not been driven hard at all since install and i dont plan on romping it for weeks.....this is going to be VERY hard not to do considering i had the cs grey mounts installed at the same time......

A new differential should be silent - if it is not I would complain about that immediately. The absence of the limited slip additive, as you know, only causes chatter in slow corners. Whining indicates the ring-gear-to-pinion clearance is wrong or the gears are worn (which presumably is not possible if the unit is truely new).

CadzillaTN
07-19-10, 01:24 PM
thanks, ill take it back.

kirchbed
07-19-10, 03:39 PM
thanks, ill take it back.

You should. I've been driving w/ a new one since Friday and it's absolutely silent.

JDB
07-19-10, 06:18 PM
The new diff is structurally different but it is still a limited slip.
That dealer doesn't know what in the world they are talking about.
The specifications I posted somewhere apply to replacement diffs as well.
It won't really do any short term damage but they need to get the modifier in there or the clutch packs are going to start grinding and making you nuts.
That is the right fluid, but they have to add 4 oz. of the friction modifier.

That's what I figured too, since it makes no sense. BUT, I called a different dealer today and they too said that they're not using the additive now.

I'm tempted to buy it or the one that Amsoil sells and put it in myself.

JNR
07-19-10, 07:37 PM
Does the fluid already contain a LSD additive, perhaps? I know some of the aftermarket ones do, but I've personally never had luck using only that and end up having to put additional LSD additive in, to avoid the chattering and lopsided wheel feeling.

I changed the diff oil this weekend (love having the plug on the bottom!) and used Mobil 1 and the equa torque stuff and seems to work pretty well. The hardest thing was determining when it was actually full, since my pump's tube wouldn't go all the way into the threaded hole (next time will put a nipple on the end of the hose that will protrude in more), so halfway thru it started dripping out...IIRc, took about 1 1/2 quarts.

I looked around and couldn't find a p/n on the housing...So, does anybody know where I could find out the p/n I have? (it's a 2007 and as I mentioned above, the guy claims the dealer upgraded it, but I'm skeptical). No issues, but I like to know what I have.

bneal1022
07-19-10, 08:53 PM
rear of diff upper passenger side mounting arm. it is a white getrag label 2"x3" at least. should not be able to miss it

JNR
07-19-10, 10:32 PM
Thanks, I will check it out next time I'm under there.

thebigjimsho
07-19-10, 11:34 PM
Yep, brought the '04 in to Lindsay the week before V-Day I and my expiring warranty. Motor mounts, diff bushing and a whole slew of items to get the V tech ready were to be done. As I was on the way down the day before to pick it up, I stopped on the NJ TP to check in on the forums to see how everything was going.

and wouldn't you know it, Bill thought the whine was too loud and was able to get me a new(latest gen) unit. Heaven is Lindsay Cadillac...

CadzillaTN
07-20-10, 01:08 AM
A new differential should be silent - if it is not I would complain about that immediately. The absence of the limited slip additive, as you know, only causes chatter in slow corners. Whining indicates the ring-gear-to-pinion clearance is wrong or the gears are worn (which presumably is not possible if the unit is truely new).

parts dept told my writer it was a new unit. the service mgr rode with me to listen...he said it would be very odd for it to be bad out of the box but acknowledged it was possible and he would return it if so...

it sang over rush hour traffic in 4th, and when i tested it tonight with the seats down it howled like a wolf on decel from 48 down to 40 in both 3rd and 4th. didnt try 5th.

im bringing her back in for another issue.. they're going to put the stethoscope on 'to rule out anything else'. dont see what it could be

JDB
07-20-10, 01:49 AM
Yep, brought the '04 in to Lindsay the week before V-Day I and my expiring warranty. Motor mounts, diff bushing and a whole slew of items to get the V tech ready were to be done. As I was on the way down the day before to pick it up, I stopped on the NJ TP to check in on the forums to see how everything was going.

and wouldn't you know it, Bill thought the whine was too loud and was able to get me a new(latest gen) unit. Heaven is Lindsay Cadillac...

Did they use the additive?

ewill3rd
07-20-10, 09:21 AM
We always put in the additive because we are literate. :lol:

Seriously though, it really boils my blood to hear you guys tell me that dealers are saying that the diff "doesn't need" friction modifier.
Ask them to show you in writing where it says that the updated diff doesn't require the friction modifier!
I have shown you guys in print where the limited slip diff calls for it.
If they say it isn't limited slip tell them to raise the car, put it in gear with the park brake released and ask them to spin a rear wheel.
After they give themselves a hernia have them explain why it isn't a limited slip and if it is, why it wouldn't require the modifier that it calls for in the manual for a limited slip diff.
Be polite :D

ewill3rd
07-20-10, 09:29 AM
PS: I just blasted them on the GM tech forum for this.
Can't wait to hear the excuses....

Junior1
07-20-10, 03:42 PM
Should of just brought the car to Lindsay and have Bill do it in the first place. It would of saved you alot of time and trouble...

thebigjimsho
07-20-10, 05:56 PM
Should of just brought the car to Lindsay and have Bill do it in the first place. It would of saved you alot of time and trouble...
Tru dat. Especially if it's under warranty, you get a free rental. 500 miles each way and I'd spend a couple Saturdays to get my V back and forth...

JDB
07-20-10, 08:00 PM
Ok, so I found another rear diff fluid here: http://www.southerncarparts.com/corvette-c6-diy-differential-oil-change-ex-43.html and under the TSB below. Apparently, my dealer was confused with this Dextron LS Gear Oil 75W-90, part #88862624 thinking that's what was going into my car, which already has the additive in it, but they put in the 89021677 fluid that requires the 1052358 that they didn't put in.

So, it has an appt on 7/31 to have the newer 88862624 put in. so, hopefully the few miles that I've put on the car didn't hurt the new gen diff that was just put in there under warranty.

----
Do not add any additives.

#10-04-20-001B: Rear Axle Clunk and/or Chatter Type Noise on Turns (Drain/Refill Rear Differential Fluid) - (Apr 21, 2010)
Subject: Rear Axle Clunk and/or Chatter Type Noise on Turns (Drain/Refill Rear Differential Fluid)

Models: 2003-2010 Cadillac CTS, Sport Wagon (Including V-Series and Export)
2004-2009 Cadillac SRX (Including Export)
2005-2010 Cadillac STS (Including V-Series and Export)
Equipped with Limited Slip Differential (RPO G80)

Condition
Some customers may comment on a clunk and/or chatter type noise from the rear of the vehicle while making turns.

This condition may be worse on vehicles built prior to the 2008 model year. Carbon-faced clutch plates were introduced into production in the 2008 model year and have decreased the likelihood of the clutch plate chatter.

Cause
This condition may be caused by slip/stick of the posi-traction clutch plates due to insufficient limited-slip axle additive. As plates slip and stick, a jumping or jerking feel occurs accompanied by a clunk noise.

Correction
Important: DO NOT remove the differential cover. It is not necessary to flush the old fluid from the differential.

Drain and refill the rear differential with fluid, GM P/N 88862624 (in Canada, 88862625). Refer to the Axle Lubricant Change procedure in SI.

This fluid includes a friction modifier already added with a different formulation that lasts longer and does not break down over time.

Without Differential Oil Cooler
1.10 L
1.16 qt

With Differential Oil Cooler
1.41 L
1.50 qt

Parts Information
Part Number

88862624 (US -1 qt)
88862625 (Canada - 1 L)
DEXRONŽ LS Gear Oil

ewill3rd
07-20-10, 09:40 PM
Ahhhh, well that would make sense.
The LS fluid was only validated for the Y cars last time I checked.
I guess they have added the V to the validated car list now.
Makes sense that IF they used Dexron LS that they wouldn't have used the modifier... however the 1677 fluid is a base synthetic fluid with no modifier.
If you can print a copy of that TSB and hand it to them they might just get you straightened out.

I will talk to the boss and we might just stock up on the Dexron LS and start using that, it is much easier to deal with anyway.
I am already using it for all the XLRs with the diff chatter on turns. Most of the ones around here have been done.

I see that update is dated April so...
I will pass that along to the other guys that I was blasting this morning.

JDB
07-20-10, 10:04 PM
Ahhhh, well that would make sense.
The LS fluid was only validated for the Y cars last time I checked.
I guess they have added the V to the validated car list now.
Makes sense that IF they used Dexron LS that they wouldn't have used the modifier... however the 1677 fluid is a base synthetic fluid with no modifier.
If you can print a copy of that TSB and hand it to them they might just get you straightened out.

I will talk to the boss and we might just stock up on the Dexron LS and start using that, it is much easier to deal with anyway.
I am already using it for all the XLRs with the diff chatter on turns. Most of the ones around here have been done.

I see that update is dated April so...
I will pass that along to the other guys that I was blasting this morning.

Yup, I handed it to them tonight after work. They're flushing out the old and putting in the new.

glad I read my invoice and did some research.

CancerJCC
07-21-10, 11:23 AM
Thanks, I will check it out next time I'm under there.

You will have to use a flash light and a small camera or camera phone to see it. It is tucked way up in there and took me probably 20 shots to finally be able to make out the first few numbers to see what I had.

JNR
07-21-10, 12:45 PM
Good tip and will also break out my inspection mirror...It's good to know where it's tucked away, cause it's pretty tight under there, especially when you're on your back!

I'm gonna keep my fingers crossed and hope that it will last; are the 2007 (and 06) oem versions that came with the car really an upgrade vs. the 04-05? People used to complain about the GTO rear too, but never had any real issues (owned new for >4 years), although I was basically stock and treated it sorta nice :D

ewill3rd
07-21-10, 11:21 PM
You can tell if it is the latest style by looking at the front.
The pinion housing is different.
Post up a pic if you can't see the label and we can tell you if it is the new style.

JNR
07-21-10, 11:51 PM
Good idea...will do hopefully this weekend (busy work week)...I did get a GMVIS report today and besides learning my warranty expired last week :( the only diff work done was:


11/27/2006 289215 # F2023 - SEAL, PINION SHAFT OIL - REAR DIFFERENTIAL - REPLACE 3603 miles

03/29/2007 296803 # F9706 - INSTALL REAR DIFFERENTIAL HOSE AND VENT (CADILLAC) 6013 miles

02/15/2008 000770 # V1777 - 07204 - REPLACE REAR DIFFERENTIAL SEAL ONLY 17245 miles


Knew the guy was full of crap and don't understand why people are the way they are sometimes; maybe passing misunderstanding off into a bs thing, don't know...I'd still like to identify the unit and will do a pic soon, I hope though. Thanks and sorry to distract the thread so much :)

ewill3rd
07-22-10, 07:50 AM
I don't see the operation for the "carrier".
It sounds like you'll see an old style diff with the updated pinion seal.

bneal1022
08-22-10, 10:09 PM
just installed my gen 4 diff. before i filled it i popped the drain to check.. and it had some fluid in it i assume they ship with a minimal amount. have no idead what it was. I added the 4oz redline break-in additive (includes friction modifier) and amsoil severe gear 75w-110. I will follow what darkman mentioned on page 3 for break-in for 500 miles.

I also did notice the new diff was significantly stiffer to rotate by hand on the input shaft over my gen 1 with 34K on it... i'll chalk this up to wear of the old one and the new one is "all tight".... at least that is what I'm lying to myself. I'm biting my nails to hope i installed correctly (sure I did) and hope to hear no whine and have new confidence in car.