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Tranny is slipping real bad all of a sudden

Sandman

New member
Long post:

The tranny started acting up real fast. I was driving around today and stopped for lunch, the car ran great all morning then after lunch the problems started, no warnings at all. I had to go to class after lunch and on the way to class the shifts were real hard and the car shuddered a lot. After class I backed out of my parking spot and put it in D, nothing. Put is in 1st and it barely moved forward, huge slip into second, and slipped into 3rd, 3rd to 4th was slow too. I now have to put the car into 1st or 2nd to start moving, and shift into 3rd and D. If I'm in D at a stop the car won't move, and if I get below a certain speed I have to shift into 2nd, no 3rd below 25-30 mph. I tried pulling into Advanced to get the codes checked and it wouldn't go up the hill, just revved. If I punch it in any gear the car will just rev, I have to take it easy for it to start to move, drives fine, no shuddering anymore, engine runs fine. I'll get a reader tomorrow and find out any codes. Anyone have ideas? 00 GTP, ~108K miles, not sure of any service ever done to the tranny.

Cliffs:
Tranny is slipping bad in first, slips in second a little, slips bad in between shifts, especially 1st/2nd.
 


It sounds like you had a pressure problem or failing pressure control solenoid which was causing the rough shifts and the result of the overly high line pressure may have broke your forward apply band-which is causing your no movement in D, and possibly blew out a channel plate gasket inside the trans which is causing excessive pressure to bleed off. Check out this thread for the forward band breaking problem...

http://www.grandprixforums.net/f21/new-guy-need-help-02-gtp-10967.html

There is likely more to it than that based on what you have mentioned but there is not a lot that can be done in the car and some teardown is going to be required to investigate.
 
I just can't believe how fast these trannys can go. I don't exactly have the money to get the tranny rebuilt. Is there anything I can look at/test besides checking codes? I may as well pull the pan and see if there is anything in there.
 
The first and easiest thing to do is drop the pan and have a peak, but aside looking at the condition of what is in the pay or looking up at the band to see if it is or is not broken there really isnt anything you can do. You could remove the filter and cut it open to see if there are a lot of contaminents inside as this will greatly effect pressure and can cause problems, but replacing the filter isnt the fix as the debris was generated to plug up the first one...that is if it is in fact full of debris.
 
That's not good, thanks for the suggestions. I'll dig into it tomorrow, what other year trannies will work with my GTP. Since I can't really afford to get the tranny rebuild I may just buy a used one in good shape.
 
If you replace your trans you are safe with a matching code transmission from another GP GTP or regal GS from 00-02 as a direct drop in. Your trans code is either going to be XA or XB. There are others that will work but this is your easiest route to going trouble free. Contact Morad Parts Company for a used trans if that is the route you want to go as they specialize in late model GM fwd cars parts.
 


I looked at the fluid this morning. Its still red, smells normal, but it is really full. The fluid is up to where the dipstick squigles, way above where it should be. Is that a bad sign too?
 
Are you checking the fluid level with the engine running? The engine needs to be running, car on level surface in Park, and warmed up for an accurate measure.
 
Its real high either way. About the same level. I'm just going to take it to a tranny shop, I just got the car fixed for completely different reasons a couple of weeks ago.
 
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