HELP!!! Transmission acting horrible, bucking, stuttering, grinding, shifting hard.

[Lsick7]

Took my 98 GTP for the first time to the track today, and lo and behold I come back with my trans acting up. I don't think it's the engine, it runs fine, and in neutral and park revs freely and no noises what so ever. Oil is fine, and vac leaks don't exist to my knowledge.

4th gear refuses to downshift on its own, it will ride 1k rpms and almost stall out completely unless I go WOT. In fact, all of the gears act that way. If I manually throw it into any gear, it bucks like crazy then finally goes into gear before stalling the car. Upshifts are very firm, but I do have a shift kit I installed, but it's incredibly firm when not in Perf Shift, and riculously uncomfortable in Performance Shift. So in short, it won't downshift, stutters like crazy, rpms are whack at idle -1500 cruise speeds in any gear, bucks like a mother when down shifted, and from a dead stop it wants to stall.

Hey, but reverse is fine!! ..... HELP PLEASE!!!!!!

[Trannyman95]

From what you are describing you will definately want to scan the car for codes and you will likely find P0742 which is TCC stuck on. This often happens when the lockup clutch lining inside the torque converter starts coming apart and contaminates the valve body and tcc solenoid. When it is stuck on it will feel like driving a manual trans car and it will lug around. Unfortunately the minimum often to repair this is a new/reman valve body and torque converter but some guys try just replacing the tcc solenoid and it works for a while but the problem comes back.

[Lsick7]

Man you are spot on! I scanned it just now and it was P0742. I drove the car about 5 minutes after letting it cool for 3 or so hours and the symptoms had disappeared. But what do suggest I do? My torque converter has been giving me fits for a while prior to this, constantly going in and out of lock-up going up hills at low rpms causing rpm spikes and stuttering. I thought that was bad, now it's ridiculous. What do you suggest? I have a spare non-hd trans if that would be easier?

Thank you so much, I've been worried sick over this.