hard/slow shifting?

[codyc]

Ok so ive done a little research and am confused as to what could be my problem with my tranny. Its in a 2003 GT Symptoms: about 10k miles ago every now and then the tranny would shift from 1-2, 2-3 really hard and then if you shut it off and parked it for a bit it would be fine. it has done this on and off for the past 10k miles and i just figured it was me getting on it and the computer setting it like that. well last weekend it did that and on monday when i started it and started driving it acted like it was low on tranny fluid, car would start moving but the rpms would be way out of normal range like i could be going 10mph and push the pedal half way down and the rpms would shoot up to 3-4k. the transmission will shift very slowly from gear to gear if you dont let the rpms go over 2500 and when it does it usually jerks a little. When the car has been warmed up and driven for a few miles it is fine, shifts normally. I have already checked the tranny fluid its clean and at the proper level. Ive read that the shift solenoid could be the culprit as well as a pressure solenoid (which makes more sense to me) but i would like some more opinions on it. It has 122k on the car and has been maintained by the book since the car was purchased in 2003.

[Trannyman95]

There are a number of things that can cause what your problems and having 122K on the trans is getting up there so wear in general is showing its signs. A failing pressure control solenoid has a large impact on what you are describing but that is not a guaranteed solution. A dirty or bad maf sensor can cause low transmission pressure also. The best way to know what is going on is to have the car properly diagnosed with a pressure gauge and a scan tool to see what is going on. Outside of diagnosing the car and verify what is or is not working correctly all you can do is guess. These transmissions are controlled completley by the pcm, so if there is something that the pcm sees out of place on the engine it will be directly related to the trans.

[codyc]

ive a scan tool ill hook it up tonight and see if there are any pending codes, it hasnt tripped a MIL yet. Would you recommend a dealer or just a repair shop for diag?

[Trannyman95]

Most shops dont have a trans pressure gauge and the ones that actually do have one seldom use it, so they will probably drive your car around the block and tell you it needs a rebuild. Its hard to find a reputable shop that isnt just out to sell the big job so I suggest asking around or checking the local BBB for complaint history. The dealerships normally charge way to much for labor/hr and dont do any better job unless you actually know someone or of them and they will diag it properly. A pressure gauge isnt absolutely necessary to someone who knows what they are looking for but it definately helps out.

[codyc]

well i had to drive it around for a few hours today to get it to throw a code but it finally threw a P0742 Torque converter clutch circut stuck on code but thats new a little different from what it was doing, before it was just shifting hard and felt like it was slipping now the code came and the torque converter was just period locked up until i reset the code with the reader. replace the tranny?

[Trannyman95]

In every scenario that I have seen that code or a customer has told me the car had that code the trans didnt make it much longer. Generally what happens is the lockup clutch lining in the torque converter starts coming apart and putting excessive debris in the valve body. In early stages it will clog up the TCC solenoid so it cant exhaust fluid well enough and the pcm cant properly control tcc operation and the code will set. Replacing the solenoid may allow it to work a while longer but the damage is likely done. After a while all the debris will get in the filter and plug it up and the car will only drive for 5-10 minutes and then lose all movement until you shut it off and let it sit for a little while and then it will move again. Replacing just the torque converter and solenoid is going to help but not fix the problem. The lockup clutch failed for a reason and that or those reasons need to be addressed and that is covered with a rebuild as long as the problem areas were repaired or upgraded.