This is a common problem with this transmission. The forward clutch piston is the likely culprit.
I do recommend that you follow the advice already given, but I would add that this is only a starting point. The transmission releases the forward clutch when it shifts to 4th gear (o/d). When coming to a stop, the same clutch is re-applied in 1st, 2nd, and 3rd gears. During a coastdown, the re-application of the clutch is prevented by hydraulic leakage from the cracked piston. There were 4 revisions of this part, with the latest being to replace the aluminum piston with a steel one that is less prone to cracking.
To answer the second part of your question.
Removing the transmission is about a half day's work outside of the shop environment. To accomplish this, you will need to support the engine from above. Then remove the subframe, being careful to support the steering rack that is attached to it so that you do not disengage the steering shaft from the column. Removal of the catalytic converter/crossover pipe is necessary to remove the subframe. Following that, the transmission can be removed from below much like a rear wheel drive transmission. You will also need a transmission jack for lowering and re-installation. Also, keep in mind that you will need to have the car raised up sufficiently to allow for removal of the transmission from underneath. Once you have removed the subframe, there is not much left to raise the car with.
Sunday, December 28th, 2008 AT 9:04 PM