Tranmission compatibility

[speedin-gtz]

I have an 89 Grand Prix with a 3.1 in it.  I managed to toast another tranny, it as shifting hard, then didn't shift into third anymore.  I have another transmission at my house that has about 20k on it.  The only problem is that it has the 4 square plug on the transmission.  My trannys has the 5 round.  I beleive the extra wire is for electronic overdrive, and the one with 4 wires has vacuum overdrive.  I am not sure though.  What i am wondering is if there is a way to take the whole plug in and assembly out and switch it?  Or can i find a plug and replace the 5 wire plug on my car?

One other thing.  The car has a hard miss when it is first started.  Feels like only 1 cylinder missing.  Can a fuel injector get stuck when its cold and open up after its warm.  The car runs fine with no more miss after running for 2 or 3 minutes.

[Guest]

The difference is that the gp sounds like it has the 440T4, while the other trans is a 125c, different computer operating systems.

[speedin-gtz]

Are the 440T4's better than the 125c's?  I also have the computer out of the car that the tranny came out of.  It was an 88 GP 2.8.  Should be the same wiring for the engine, but I am sure about what wires i would use for the tranny since i'd have to eliminate one.  If that is even possible.

[Guest]

Quote (speedin-gtz @ Jan. 30 2003,09:02)Are the 440T4's better than the 125c's?  I also have the computer out of the car that the tranny came out of.  It was an 88 GP 2.8.  Should be the same wiring for the engine, but I am sure about what wires i would use for the tranny since i'd have to eliminate one.  If that is even possible.
I wouldn't count on the wiring being the same. You're talking about two different divisions of GM, and if they were the same, the computers would be the same, etc, etc, etc, but it doesn't work like that. Pontiac designs what they want, the way they want, and chevy does what they want, olds does something different than the other 2. You get the picture, it's not a matter of cutting a wire. Cutting a wire, may cause several other things to go out of wack, and you'll really have trouble. I don't think a 440t4 will even fit in place of a 125c mounting, let alone getting it to work properly. In the long run, I think you'll find it cheaper to just replace the 125c with another 125c.  

[speedin-gtz]

They are both grand prix's.  I know I can get another 125c for 125 bucks for the JY, but I already put one of those in there and it just puked on me.  I was out testing the car after getting it running again, seeing if it was road worthy and it was dumping into gear really hard, then blew out shifting into third, first and second still work.  I wanted to use this other tranny do to the fact that i know its history unlike the jy ones.  But oh well, i will just get another one from the jy.  And if anyone wants a 440t4, i'll sell it pretty cheap.

[Guest]

What make model did the 440t4 come out of???   Im in need I just havent made sure which tranny yet..   How much to sell???  My JY prices seem to run @the same as yours..(Interesting) YES???