1999 Grand Prix differential EXPLODED
13 shorty
04-22-2011, 10:37 AM
so i was driving the other day and when i went to accelerate rather quickly, the differential exploded out the bottom. i have no clue what im doing but im going to attempt to pull it out and replace it. I have done engine work and am very familiar with my car but never touched the tranny and i can not afford to take it in. if anyone has advice or know how on how to do this, i would greatly appreciate it.
Stealthee
04-22-2011, 07:27 PM
No point in lying to us about it. Just say it. You went to launch it. ;)
I have never pulled a trans in a GP but from what I hear its not easy. You have to remove the engine cradle to do so. Unless you have the proper tools and equipment you are going to have a difficult time doing it on your own.
I have never pulled a trans in a GP but from what I hear its not easy. You have to remove the engine cradle to do so. Unless you have the proper tools and equipment you are going to have a difficult time doing it on your own.
olopezm
04-22-2011, 07:40 PM
Welcome to the forum shorty!
Stealthee is right, you need to either remove the cradle and remove the transmission from under the car or remove the engine with the transmission still attached to it (that's the way I did it when mine exploded too!). There are two differentials available and are the same size, the only difference is the number of teeth, AFAIK one provides more acceleration and the other more speed (someone correct me if I'm wrong), each corresponds to the transmission on the GT and the GTP (4T65E and 4T65E HD respectively). Both differentials are interchangeable, when I did mine I couldn't find the exact replacement and only found the one with more teeth (the transmission on mine is 4T60) I decided to go with it and after 6 years it's working great!.
If you have worked with transmission you should have no problems at all, if you haven't just work on a clean area and make sure you note the position of the internal components once you take it out, failure to do so will result in malfunction. When you remove the valve body make sure you don't loose the small steel balls in it. Since you are removing it, it would be a good idea to make a rebuild...
Oscar.
Stealthee is right, you need to either remove the cradle and remove the transmission from under the car or remove the engine with the transmission still attached to it (that's the way I did it when mine exploded too!). There are two differentials available and are the same size, the only difference is the number of teeth, AFAIK one provides more acceleration and the other more speed (someone correct me if I'm wrong), each corresponds to the transmission on the GT and the GTP (4T65E and 4T65E HD respectively). Both differentials are interchangeable, when I did mine I couldn't find the exact replacement and only found the one with more teeth (the transmission on mine is 4T60) I decided to go with it and after 6 years it's working great!.
If you have worked with transmission you should have no problems at all, if you haven't just work on a clean area and make sure you note the position of the internal components once you take it out, failure to do so will result in malfunction. When you remove the valve body make sure you don't loose the small steel balls in it. Since you are removing it, it would be a good idea to make a rebuild...
Oscar.
helicopter23
01-10-2013, 03:36 AM
No point in lying to us about it. Just say it. You went to launch it. ;)
I have never pulled a trans in a GP but from what I hear its not easy. You have to remove the engine cradle to do so. Unless you have the proper tools and equipment you are going to have a difficult time doing it on your own.
Same thing happened to me I think... How much would this repair cost ???
I have never pulled a trans in a GP but from what I hear its not easy. You have to remove the engine cradle to do so. Unless you have the proper tools and equipment you are going to have a difficult time doing it on your own.
Same thing happened to me I think... How much would this repair cost ???
Tech II
01-10-2013, 10:35 AM
You don't say what year......
A new rebuilt, $2K dollars, then labor to install....
Junkyard, maybe 400-500......but new seals and complete valve body should be installed prior to installation......
A new rebuilt, $2K dollars, then labor to install....
Junkyard, maybe 400-500......but new seals and complete valve body should be installed prior to installation......
helicopter23
01-10-2013, 11:45 AM
You don't say what year......
A new rebuilt, $2K dollars, then labor to install....
Junkyard, maybe 400-500......but new seals and complete valve body should be installed prior to installation......
97 grand prix gt 145k. Guy that works on my car said for a used trannsmissions for parts and labor $900 total ?? Transmission comes with either 30 day or 90 day warrantly... debating if I should get job done.
A new rebuilt, $2K dollars, then labor to install....
Junkyard, maybe 400-500......but new seals and complete valve body should be installed prior to installation......
97 grand prix gt 145k. Guy that works on my car said for a used trannsmissions for parts and labor $900 total ?? Transmission comes with either 30 day or 90 day warrantly... debating if I should get job done.
Automotive Network, Inc., Copyright ©2026
