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7K views 32 replies 13 participants last post by  CadV 
#1 · (Edited)
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.
 
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#2 ·
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.
 
#4 ·
Beat the hell out of an automatic transmission?
 
#5 ·
I don't think it's that hard to abuse even an automatic tranny. People do all sorts of bad things during test drives.
 
#8 ·
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.
 
#18 ·
My guess is fluke. We'd have heard of more by now.
 
#10 ·
^^^^^
So should I not use the w4m tranny tune? I don't think its THAT aggressive a tune? Haven't put it on yet.
 
#11 ·
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.
 
#12 ·
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.
 
#14 ·
I'm cool then. :thumbsup: Thanks for answering as I know precisely nothing about tranny programming. :)
 
#15 ·
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.
 
#16 ·
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.
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anyone notice the tune or ask about any changes like a tune, dealer, GM or who ever after the failure?
 
#20 ·
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.
 
#32 ·
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.
 
#25 ·
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...
 
#27 ·
I use the highest octane available here--93. However, I think my issue is more a GM programming issue.
 
#29 ·
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.
 
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