Auto Trans Problems - need advice!
Thread Starter
Heel & Toe
Joined: May 2005
Posts: 21
Likes: 1
Auto Trans Problems - need advice!
My 01 automatic has serious problems. I recently replaced the stock 2.72 rear end with a 3.43. The first test drive revealed the fact that the tranny needed to be reprogramed. It was hitting the rev limiter at WOT before shifting. I took it to my local LS1 edit shop and they set it up to shift at appropriate times. For a few days it ran fantastic! Tremendous torque increase. I occasionally smelled something burning which I now believe was cluches. Then during a trip over a mountain road one day the check engine light came on. Shortly after, the transmission began to shift so hard it would rattle your bones. I mean serious slamming. I limping it back to the shop by starting in second leaving only the 2 to 3 shift which was very hard although nothing like the 1 to 2 shift.
Strangely, when cool it shifts perfectly until it heats up and begins slamming again. Unfortunately, the LS1 shop now says they can't get it to act up. (typical). In any case, they are dealing with the check engine code/s and will give it back to me today. My feeling is that the problem will resurface. Any ideas would be greatly appreciated.
Strangely, when cool it shifts perfectly until it heats up and begins slamming again. Unfortunately, the LS1 shop now says they can't get it to act up. (typical). In any case, they are dealing with the check engine code/s and will give it back to me today. My feeling is that the problem will resurface. Any ideas would be greatly appreciated.
Safety Car
Joined: Jun 2003
Posts: 4,509
Likes: 239
From: Coconut Creek FL
Sounds to me like the tune was no good- the torque converter is either staying in full lockup or its not locking up- sounds like both...what are the temps? was it normal before the gear swap? heat will kill it- so I would not drive it without making damn sure they have it tuned correctly...
Originally Posted by pmruss
My 01 automatic has serious problems. I recently replaced the stock 2.72 rear end with a 3.43. The first test drive revealed the fact that the tranny needed to be reprogramed. It was hitting the rev limiter at WOT before shifting. I took it to my local LS1 edit shop and they set it up to shift at appropriate times. For a few days it ran fantastic! Tremendous torque increase. I occasionally smelled something burning which I now believe was cluches. Then during a trip over a mountain road one day the check engine light came on. Shortly after, the transmission began to shift so hard it would rattle your bones. I mean serious slamming. I limping it back to the shop by starting in second leaving only the 2 to 3 shift which was very hard although nothing like the 1 to 2 shift.
Strangely, when cool it shifts perfectly until it heats up and begins slamming again. Unfortunately, the LS1 shop now says they can't get it to act up. (typical). In any case, they are dealing with the check engine code/s and will give it back to me today. My feeling is that the problem will resurface. Any ideas would be greatly appreciated.
Strangely, when cool it shifts perfectly until it heats up and begins slamming again. Unfortunately, the LS1 shop now says they can't get it to act up. (typical). In any case, they are dealing with the check engine code/s and will give it back to me today. My feeling is that the problem will resurface. Any ideas would be greatly appreciated.
Team Owner
Joined: May 2004
Posts: 26,345
Likes: 231
From: SoCal
I'm no expert but I had similar issues in the past.
If the tune for the gear swap is not correct the PCM will see excess slippage and throw the tranny into fail safe mode. This will be short/hard shifts that generate little heat.
Post your codes so that the guys that really know can help you...
DH
If the tune for the gear swap is not correct the PCM will see excess slippage and throw the tranny into fail safe mode. This will be short/hard shifts that generate little heat.
Post your codes so that the guys that really know can help you...
DH
Burning Brakes
Joined: Sep 2004
Posts: 1,056
Likes: 0
From: Havelock, NC ( NJ Resident )
I bet THIS IS THE CODE
Originally Posted by Dirty Howie
I'm no expert but I had similar issues in the past.
If the tune for the gear swap is not correct the PCM will see excess slippage and throw the tranny into fail safe mode. This will be short/hard shifts that generate little heat.
Post your codes so that the guys that really know can help you...
DH
If the tune for the gear swap is not correct the PCM will see excess slippage and throw the tranny into fail safe mode. This will be short/hard shifts that generate little heat.
Post your codes so that the guys that really know can help you...
DH
I believe that the code he will bring up is is P1870,and I hope that the tunner hard coded the change of gear ratio when completed the tune
Team Owner
Joined: Apr 2001
Posts: 54,204
Likes: 180
From: S.W. Ohio. . . . . . NRA Life Member
Originally Posted by Dirty Howie
...
If the tune for the gear swap is not correct the PCM will see excess slippage and throw the tranny into fail safe mode. This will be short/hard shifts that generate little heat.
If the tune for the gear swap is not correct the PCM will see excess slippage and throw the tranny into fail safe mode. This will be short/hard shifts that generate little heat.
I think it's this simple... assuming all the mechanical aspects of your rear carrier swap are fine... then it's all in the programing. The C5 is unique, and only someone experienced with C5's will know everything that will need changed.
Sounds like your programer didn't adjust the TCC slip table
Thread Starter
Heel & Toe
Joined: May 2005
Posts: 21
Likes: 1
Auto Tranny Problems - Thanks for the replies
I appreciate the advice on this. The shop that programed this I THOUGHT was pretty good. The code that I read with my code reader is 1870. Again, the car runs perfectly until it has been at freeway speed for a period and get's near 200 degrees. The other thing I forgot to mention is the smell. I do smell what I think is burned fluid or clutches.
Team Owner
Joined: May 2004
Posts: 26,345
Likes: 231
From: SoCal
Originally Posted by pmruss
I appreciate the advice on this. The shop that programed this I THOUGHT was pretty good. The code that I read with my code reader is 1870. Again, the car runs perfectly until it has been at freeway speed for a period and get's near 200 degrees. The other thing I forgot to mention is the smell. I do smell what I think is burned fluid or clutches.
It will take less than 30 minutes !!!!!!!!!!
DH
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Instructor
Joined: Feb 2005
Posts: 242
Likes: 2
From: Mims Florida
2.73 to 3.42 gear change ?
I am in the middle of the same gear change on my 99 coupe. I bought the Predator to change the shift mile per hour points. Am I still going to get the TCC slip code 1870 after doing this??? 
Team Owner
Joined: Apr 2001
Posts: 54,204
Likes: 180
From: S.W. Ohio. . . . . . NRA Life Member
Originally Posted by vettezeke
I am in the middle of the same gear change on my 99 coupe. I bought the Predator to change the shift mile per hour points. Am I still going to get the TCC slip code 1870 after doing this???
there are three model Predators for the C5.
* 1999 through 2003 exclusive
* 2003 only
* 2004 only
the first one (1999-2003 exclusive) has a software bug that won't allow it to take care of the TCC slip error when changing rear axle ratios on the A4. Diablosport has a software patch that will take care of it. Contact them (ask specifically for Johan), or the dealer you purchased it from.
Until you get your Predator updated, clear the P1870 code and drive in "3" instead of overdrive. That should keep the P1870 from being set.
Thread Starter
Heel & Toe
Joined: May 2005
Posts: 21
Likes: 1
More on my shift problems
I have shared the comments from this forum with my programer who listened with interest. He called the author of LS1 and discussed some of your comments. He claims to have a plan and wants the car tomorrow. Will let you know the results. Thanks for the help.