98 GTP Tranny

[eganz84]

I have 98 Gtp with 125k miles on it. I got the car a year ago and it has always had a wierd shift... 1st and second are fine but when shifting to 3rd i need to take the car all the way up to 2800 rpm and it then shift into what im guessing is 4th because there are no more shifts after that. Rpm go down to about 1800 rpms...(note: when put under a lot of load on the highway like going up a long hill if i went down to about 45 mph it would down**** to 2nd gear but not shift back until i got off the highway and went slow for a good while) it was running fine like this for over a year, about a month ago i added soom metal lube now it has a slight shudder in 2nd and a nasty one in "4th" special between 55 and 70 mph.. above that it doesnt bother much unlees put under heavy load.. to me it seems as iff the tcc is stuck to the 3rd gear and after the metal lube its trying to separate and work how it should.. any help please planning on an tranny oil and filter change soon(note: it gives a P0741 code... tcc stuck off i think???)

[The Chad]

Hey eganz84, welcome to the forums. I'm a newbie, too. I'm looking for help myself with a tranny problem, but I ran across some info on here that may help you... it's from the Triple Edge Performance website:
Tach bounces up and down a few hundered rpm while cruising in lockup:
Another common problem / concern of this transmission and more pronounced with added engine power or higher mileage. This generally happens when the valve body has excess wear in the TCC valve area. Excessive fluid leakage in this area of the valve body causes TCC apply pressure loss and can lead to uncontrollable TCC operation which causes the engine rpm to bounce up and down a bit. This problem is noticed most after driving a while and speeds between 42 and 70mph and in 4th gear. There are other causes to this problem that can be from worn or shrunken teflon seals on the input shaft, a bad o-ring on the input shaft that seals in the torque converter, a faulty torque converter clutch, and even a bad pressure control solenoid. Another common occurance is a worn out sleeve in the channel plate that supports the input shaft. When this sleeve wears the input shaft will get chewed up where the sealing rings are and cause problems. Commonly code P0741 will be found in the pcm memory as a stored code and is described as Torque Converter Clutch Stuck Off. When this happens adaptives shifts are disabled, TCC operation is disabled, and 4th gear can be disabled. Generally a new or reman / repaired valve body will correct this condition and a new EPC solenoid is always suggested as well. The TCC/PWM solenoid is rarely ever at fault and I am yet to find one bad. Again the valve body is the common cure BUT not always the culprit and certainly not the whole problem after this has been happening for a while. Any time a torque converter fails there will be debris going back into the trans. There is a pressure relief valve in the channel plate that will collect debris from a bad torque converter and reduce cooler flow, cause trans to run hot, and greatly effect TCC operation and can destroy a new converter in a matter of miles if this isnt carefully inspected or upgraded. The best way to verify proper operation as commanded by the pcm is with a scan tool by viewing TCC slippage rpm, TCC duty cycle, EPC data, and checking any codes and making sure the engine is running properly and a misfire is not a false sense of a torque converter problem or shudder.
Check out the thread it's from, http://www.grandprixforums.net/f21/0...lem-10549.html
I've had two GTP's, a '00 and still own a '01. Have/had tranny issues with both, it's unfortunately common on these vehicles. Search these forums carefully, it takes a long time, but you can usually find someone else with the same problems as you have. Hope I was able to help you a little.

[eganz84]

Thanks Chad...
Update.. After the oil and filter change all the tranny problems i had stopped. but now the one i had from the code is going... my tcc is stuck so iff yall know what the easiest way to fix it would be greatly apreciated..