• The site migration is complete! Hopefully everything transferred properly from the multiple decades old software we were using before. If you notice any issues please let me know, thanks! Also, I'm still working on things like chatbox, etc so hopefully those will be working in the next week or two.

98 GTP tranny problems

pontiacGTP123

pontiacGTP123

New member
I installed a 99 DHP in my 98 GTP it seems to run fine, great power. Ive had it in for about a week now no problems until it got cold last night and this morning. I has been shifting so smooth but last night it shifted really firm and quick. This morning I started it and let it warm up about 7 minutes before I left. It shifted smooth again for about 10 minuted but then started shifting really firm and quik again. Also when It goes into 4th gear it fills like I ran over a bump in the road as its shifting. kind of like a suddem mild jerk. Could It be the temperature changing from hot to cold? Its was around 45-55 degrees between last and this morning. Is this normal?
 


Ummm...could be the 4th clutch taking a crap on you. They are kinda known to do that but you don't have hardly any mods idk. Plus you mean firm and quick...the DHP PCM cranks up the tranny line pressure so it does that. Try turning OFF Performance Shift.
 
Its been off when it does it. How hard is it to replace the clutch? I guess I would have to remove the tranny to do so. Also would a shift kit help out?
 
pontiacGTP123 said:
Its been off when it does it. How hard is it to replace the clutch? I guess I would have to remove the tranny to do so. Also would a shift kit help out?
Click to expand...

You know anything about transmissions? Ask Dave...trannyman95 about replacing that 4th Clutch...I think if memory serves me you basically gotta pull the entire thing apart...EVERY...LITTLE...PART.
 
Not for the fourth clutches. Just gotta take the side cover off. It's a bit of a job just to get that far, though. The fourth clutches are actually recessed in the side cover itself.
 
I have noticed my 4th gear shift kinda thumps. It done that before the rebuild and still does it after. I have a DHP as well, but it is a 98 PCM in a 98 car, I dont think the fact of it being a different year would have anything to do with it in your case. I have an Overkill PCM on the way, so I will get to see if there is any improvement.
The fourth gear clutch set and chain is accessible with out pulling the tranny, but you have to get to the side cover and there are several things you will need to remove. It is not a job for anyone that does not have some decent mechanical skills.
 


You must log in or register to reply here.
Back
Top