Tranny issues?
12-20-2004, 12:50 AM
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Tranny issues? Ok, i think im going to start from the beginning to give ya'll an idea of my issues. I bought a 00' Trans am WS6 (supercharged) last febuary and the second day I had it the transmission went out (its got a re-built A-4). I took it back the transmission shop that originally built the tranny and they did the same thing, rebuilt the tranny with some of the clutch upgrades ect...
Several months later i noticed it starting to slip again and then one day driving on the freeway i lost 3rd and OD.
Took it to a new tranny shop and they told me what i already knew, that all the high clutches were toast, although they werent completly sure why i continue to have the same issues.
I couldt afford the $2100 rebuild so I decided to buy a friends rebuilt tranny (that was originally in a 10 sec car and no problems whatsoever)
The test drive with the new tranny didnt go as well as i had hoped. The car would not shift at all into third, and when i put the car in reverse it died...
Now im starting to wonder if it wasnt the transmission in the first place (and still hoping that this new tranny isnt done for as well)
If anyone has any input it would be GREATLY appreciated. I kind of would like to know where to start, what I should look for ect.....
Several months later i noticed it starting to slip again and then one day driving on the freeway i lost 3rd and OD.
Took it to a new tranny shop and they told me what i already knew, that all the high clutches were toast, although they werent completly sure why i continue to have the same issues.
I couldt afford the $2100 rebuild so I decided to buy a friends rebuilt tranny (that was originally in a 10 sec car and no problems whatsoever)
The test drive with the new tranny didnt go as well as i had hoped. The car would not shift at all into third, and when i put the car in reverse it died...
Now im starting to wonder if it wasnt the transmission in the first place (and still hoping that this new tranny isnt done for as well)
If anyone has any input it would be GREATLY appreciated. I kind of would like to know where to start, what I should look for ect.....
12-21-2004, 11:09 AM
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I think the transmission control part of the PCM tune wants
a lot of work. If you are maxing out the MAF and/or running
around with a 1-bar MAP the PCM is getting fooled pretty
badly about the applied torque and perhaps not giving full
pressures when they are really needed.
This is not the kind of thing that dyno-based or mail order
tuners are good for, you really need to be looking at what
goes on, on the street - esp. tranny slip PIDs and line
pressure, force motor PWM PIDs under mid throttle where
boost may be high but the trans may be still getting told to
apply less than full pressure when it needs all it can get.
a lot of work. If you are maxing out the MAF and/or running
around with a 1-bar MAP the PCM is getting fooled pretty
badly about the applied torque and perhaps not giving full
pressures when they are really needed.
This is not the kind of thing that dyno-based or mail order
tuners are good for, you really need to be looking at what
goes on, on the street - esp. tranny slip PIDs and line
pressure, force motor PWM PIDs under mid throttle where
boost may be high but the trans may be still getting told to
apply less than full pressure when it needs all it can get.
