: Transmission Failure Diagnosis



jwa999
06-09-09, 07:03 PM
Last week my transmission failed. Got a new one today and picked up the car. So i'm going to baby it for a while.

For anybody interested, this is the report:

"6187 Transmission trying to tie up when commanding 5th and 6th gear. Removed trans and found 1-2-3-4 and 4-5-6 clutches burnt. K7000 6.20 air checked housings, checked necessary pistons, disassembled valve body and inspected valves. Was unable to find problem explaining why clutches burnt. Called techical assistance and they suggested resealing effected drums and replace burnt clutches, upper and lower valve bodies, and TCM assembly. Called P.Q.C. to get authorization for TCM assembly. After talking with engineer for a few minutes, he declined TCM assembly and wanted to replace trans assembly due to milage and no definite as to why clutches burnt. Placed trans assembly per P.Q.C., flushed cooler, topped off with fluid and test drove. Programmed TCM. Flush code 3BFBE07 .8 GPM @ 79 DEG. G.M. CASE # 10879872"

New transmission costs around $2500. (total was $3400, but included car rental and their work). Warranty payed for it of course. (New transmission is cheaper than a clutch job on the porsche!)

On delivery of the vehicle, left front (polished) wheel got scratched up. So it will have to go back again, but 'ill wait till next week!

Hans.

neuronbob
06-09-09, 07:21 PM
So they don't know why the clutches burned out. Sounds a little worrying to me. I wonder whether it was simply poor assembly given the relatively early failure.

jwa999
06-09-09, 07:32 PM
Or somebody beat the hell out of it during test drives. It was one of the first Vs at that dealership, it has 134 miles on it when i bought it. It failed at 6100 miles.

CVP33
06-09-09, 07:47 PM
Beat the hell out of an automatic transmission?

neuronbob
06-09-09, 10:39 PM
I don't think it's that hard to abuse even an automatic tranny. People do all sorts of bad things during test drives.

musclesbmf
06-10-09, 08:30 AM
What were the symptoms you were experiencing?

thanks,
Mark

CIWS
06-10-09, 09:20 AM
Glad to see you have your V back Hans. :thumbsup:

It will be interesting to see if your case is a fluke or a trend.

jwa999
06-10-09, 11:07 AM
What were the symptoms you were experiencing?

thanks,
Mark

Transmission completely locked up going to 5th gear. That's why the clutches where burned. Car would start to slow down fast when it hit fifth gear.
Just got it back and the trans temps where around 150. The morning I brought it in, driving slowly, the trans temps where already 180.
I had about 2000 miles of performance max tune on it. Don't think that was the cause. Restored to stock before i brought it in and they never questioned it. Of course I'm now questioning if I should reapply the tune...

Hans.

McRat
06-10-09, 12:10 PM
Transmission completely locked up going to 5th gear. That's why the clutches where burned. Car would start to slow down fast when it hit fifth gear.
Just got it back and the trans temps where around 150. The morning I brought it in, driving slowly, the trans temps where already 180.
I had about 2000 miles of performance max tune on it. Don't think that was the cause. Restored to stock before i brought it in and they never questioned it. Of course I'm now questioning if I should reapply the tune...

Hans.

What I do know,

With the programmable Allison Automatic, both ECM and TCM programming has been responsible for "tie-ups" which toast the clutches and even damage hard parts. Not all programming, just some programming. There are racers who would trash transmissions after just 3 quarter mile passes with too aggressive of tuning.

Does this apply to the 6L90? Can't say. But you cannot accelerate between gears, nor accelerate during a tieup. Tie ups often feel like a "bang" on a shift at high throttle settings. Kinda like shifting a motorcycle without the clutch. IMO, the fastest automatic ET's we ran had shifts that you barely feel, just the rpm falls, which means there is still some shift defueling occuring. Bang shifting felt faster, but it wasn't.

This might not apply, and I'm not saying ECM/TCM tuning is bad either. But at least on some GM automatics, tuning can indeed cause premature failure.

neuronbob
06-10-09, 01:31 PM
^^^^^
So should I not use the w4m tranny tune? I don't think its THAT aggressive a tune? Haven't put it on yet.

McRat
06-10-09, 02:00 PM
^^^^^
So should I not use the w4m tranny tune? I don't think its THAT aggressive a tune? Haven't put it on yet.

Naw, all I'm saying is that with another GM trans (Allison) that SOME tuning changes can bust the trans in very short order, and has happened quite a bit. Other tuning actually helps the trans survive high output. We run huge amounts of power through the Allison though. 1500+ ft/lb, 800+ rwhp. Tie-ups are lethal.

Could the same thing happen with 6L90 at far lower power increases? I cannot say. Time will tell though. Allisons are much different internally, and not all autos can tie up. Guess I have to do some 6L90 research.

wait4me
06-10-09, 02:10 PM
There are NO changes made for 5th and 6th gear in my tunes. Those to me are not considered a PERFORMANCE gear so i leave all that stock. All changes are in 1- 4th. That is where all the performance gains are to be had anyways.

wait4me
06-10-09, 02:13 PM
^^^^^
So should I not use the w4m tranny tune? I don't think its THAT aggressive a tune? Haven't put it on yet.


My trans tunes arent agressive. Anyone asking for an agressive tune or to take out torque managment, i tell them no and that it will damage the trans..

You can also damage the trans by asking for too fast of a shift, and also to much line pressure.

This isnt new technology, It is a trans type used since 2005... I have cars running 60,000 miles plus in the STSv with the WEAKER transmission.....

neuronbob
06-10-09, 02:40 PM
I'm cool then. :thumbsup: Thanks for answering as I know precisely nothing about tranny programming. :)

jwa999
06-10-09, 02:56 PM
It really feels like a one off failure. I'm an aggressive driver, had the car upto 140 a couple of times. Never on a drag strip. Will launch from a stoplight trying to avoid wheel slip. Fooled around a little bit with brake launching, but not much. Just a little revving to 1000rmp before letting go of the brake already launches the car great. The failure occurred less than 2 minutes after I started it and drove away from my office sunday before last. I had driven it a few hours earlier. I remember it revving higher then usual in the second corner and the next moment it failed.
The transmission always operated very smoothly with the tune, never any problems.

Hans.

vperl
06-10-09, 04:33 PM
It really feels like a one off failure. I'm an aggressive driver, had the car upto 140 a couple of times. Never on a drag strip. Will launch from a stoplight trying to avoid wheel slip. Fooled around a little bit with brake launching, but not much. Just a little revving to 1000rmp before letting go of the brake already launches the car great. The failure occurred less than 2 minutes after I started it and drove away from my office sunday before last. I had driven it a few hours earlier. I remember it revving higher then usual in the second corner and the next moment it failed.
The transmission always operated very smoothly with the tune, never any problems.

Hans.

&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&

anyone notice the tune or ask about any changes like a tune, dealer, GM or who ever after the failure?

jwa999
06-10-09, 05:55 PM
&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&

anyone notice the tune or ask about any changes like a tune, dealer, GM or who ever after the failure?

Nop. Like I said, i had returned it to stock, put the covers back on, and nobody asked me if I had made any changes.

Hans.

CVP33
06-10-09, 06:54 PM
Glad to see you have your V back Hans. :thumbsup:

It will be interesting to see if your case is a fluke or a trend.

My guess is fluke. We'd have heard of more by now.

rp161
06-11-09, 01:53 PM
I hope your right on it being a fluke. I hate going back to the dealer.

GMX322V S/C
06-12-09, 05:09 AM
Nop. Like I said, i had returned it to stock, put the covers back on, and nobody asked me if I had made any changes.

Hans.Hans, occasionally I get a "very slow" 1-2 shift when pulling away after startup--whether cold or warmed up. By very slow I mean I'm at part throttle and during that very first 1-2 shift the engine sometimes revs up yet the car actually slows acceleration to the point where my head dips forward a bit. After that initial occurrence, everything's fine. Did this ever happen to you? I'm also running Wait4Me's max performance tune. Just curious.

jwa999
06-12-09, 06:02 AM
Hans, occasionally I get a "very slow" 1-2 shift when pulling away after startup--whether cold or warmed up. By very slow I mean I'm at part throttle and during that very first 1-2 shift the engine sometimes revs up yet the car actually slows acceleration to the point where my head dips forward a bit. After that initial occurrence, everything's fine. Did this ever happen to you? I'm also running Wait4Me's max performance tune. Just curious.

I haven't applied any tune yet, but the new tranny seems to be smoother. Hasn't been jerky at all. Almost feels like they updated the tcm, but then I'm not very aggressive yet. Old transmission would be jerky, especially between 2-3. With jerky I mean what you say, it takes a while to shift and when it ends up in the new gear, the engine revs no longer match and the car slows down somewhat. After the tune that transmission was a lot smoother.

I believe in the standard mode, the car will start in 2nd gear, so your 1-2 might actually be 2-3.

Hans.

CIWS
06-12-09, 08:50 AM
I haven't applied any tune yet, but the new tranny seems to be smoother. Hasn't been jerky at all. Almost feels like they updated the tcm, but then I'm not very aggressive yet.

Might be a sign they have an updated TCM flash since your car was originally delivered, or it could also be a sign there was something funky in/about your original transmission that culminated in the clutch failure.

GMX322V S/C
06-12-09, 05:02 PM
...I believe in the standard mode, the car will start in 2nd gear, so your 1-2 might actually be 2-3.

Hans.Thanks for the feedback. I get this occasional "slow shift" when pulling away for the first time, so it's a 1-2 shift in either mode. Good luck with the new tranny!

ctsv5005
06-13-09, 04:59 AM
Hans, occasionally I get a "very slow" 1-2 shift when pulling away after startup--whether cold or warmed up. By very slow I mean I'm at part throttle and during that very first 1-2 shift the engine sometimes revs up yet the car actually slows acceleration to the point where my head dips forward a bit. After that initial occurrence, everything's fine. Did this ever happen to you? I'm also running Wait4Me's max performance tune. Just curious.


Same is my case.

neuronbob
06-13-09, 05:56 AM
I don't get a slow shift, but MAN does this automatic tranny love to hold a gear in regular D mode. Sometimes it's at the wrong time and the tach sticks at 3k rpm (for example) until I blip the throttle a little extra to get the computer to shift the car. usually it happens after I've accelerated onto the freeway and have caught up to slower traffic, then have to let off the throttle...then the gear is held, almost as if it's waiting for me to accelerate more. I'm not running the W4M tune yet, though...

ctsv5005
06-13-09, 06:06 AM
I don't get a slow shift, but MAN does this automatic tranny love to hold a gear in regular D mode. Sometimes it's at the wrong time and the tach sticks at 3k rpm (for example) until I blip the throttle a little extra to get the computer to shift the car. usually it happens after I've accelerated onto the freeway and have caught up to slower traffic, then have to let off the throttle...then the gear is held, almost as if it's waiting for me to accelerate more. I'm not running the W4M tune yet, though...

hmmm... not happened with me... just a little jerk from 1-2 when start the car and drive. what octane do you use? it used to happen in my other car but i went with higher octane and the issue was solved. try different octane.

neuronbob
06-13-09, 08:34 PM
I use the highest octane available here--93. However, I think my issue is more a GM programming issue.

jwa999
06-13-09, 08:54 PM
MAN does this automatic tranny love to hold a gear in regular D mode.

Funny that you mention this. This did not happen in my V, but the loaner 3.6 CTS that I got. It had 140 miles on it when i got it. So was breaking it in, running it in different gears at medium revs. The day I brought it back, now at 440 miles, it just would just not upshift out of 3rd gear. It would rev to 6-7000 rpms and just stay there in sport tranny mode. I couldn't get it to kick to 4th.
Must have been the tranny-adapts-to-the-driver programming.

That should never ever happen in the regular D mode.

Hans.

Flavoade
06-13-09, 10:06 PM
I did not know anyone actually bought an HPV off of the dealer's lot. The 130 miles that it had on it were probably really hard miles; I'm talking burnouts, and red-line shifts. I remember when the new M3's came out. By the weekend the rear tires on all three of the dealers stock were bald. Neglectful test drivers, and ignorant sales agents kill those cars. Thats why I will not buy an HPV that is on a dealers lot. If I like the car, I will order my own and just wait for it to come in.

It was likely just an unlucky car. Though GM does build a good deal of their transmissions in Mexico.

ctsv5005
06-14-09, 01:38 AM
I use the highest octane available here--93. However, I think my issue is more a GM programming issue.

go for w4m tune, and your issue will be solved, trust me.

CadV
06-15-09, 08:47 AM
Nop. Like I said, i had returned it to stock, put the covers back on, and nobody asked me if I had made any changes.

Hans.

Smart man

CadV
06-15-09, 08:52 AM
Hans, occasionally I get a "very slow" 1-2 shift when pulling away after startup--whether cold or warmed up. By very slow I mean I'm at part throttle and during that very first 1-2 shift the engine sometimes revs up yet the car actually slows acceleration to the point where my head dips forward a bit. After that initial occurrence, everything's fine. Did this ever happen to you? I'm also running Wait4Me's max performance tune. Just curious.


Thanks for the feedback. I get this occasional "slow shift" when pulling away for the first time, so it's a 1-2 shift in either mode. Good luck with the new tranny!

This has happened to me before. It use to happen a lot in my STS-V. It happened once in my V when I first got it. Since then I swapped the fluid to Amsoil and got Jesse's tune and it has not happened again. I don't know if either affected it or if it was a fluke.

CadV
06-15-09, 08:55 AM
When I got my crank done Matt from SNL checked out Jesse's tunes and said everything looked good. Not to aggressive.

He was running a scan on the car when we were test driving it and everything was normal.