91 Gtp

[kyledel]

where on the transmission should this tag be roughly?

[kyledel]

I meant to say where on the final drive is the tag located but my edit button is not working. Also how difficult is switching final drives? is it just a matter of unbolting the final drive from the transaxle?

[kyledel]

I am also curious as to how the final drive gear would cause this? Is it a compatibility issue with the computer?

[wafrederick]

The wrong gear ratio,it will not work.It is real easy to remaove,remove the cover and the final drive is held in with a c clip using two flat bladed screwdrivers being careful not losing the clip or using the special tool made by Kent Moore which is not cheap.Look for a white tag with 2 big letters near the final drive cover near the back

[kyledel]

Is it the wrong gear ratio for the computer? im sorta confused but anyways i looked for the tag and i remember seeing it before but it appears to have been removed but the swap sounds easy so i think i will go ahead and do it. Swapping them out can only be for the better right? because im either going from the wrong final drive to the right final drive or the right drive to the right drive again right?

[tblake]

Yeah, but you will have to disasemble the trans to get the final drive out.

Hang tight on the wiring diagrams, i'll get them asap for you.

[tblake]

Here are the diagrams I promised you. There were two different ones for a 1995 GP, one with 3.4L and the other with a 3.1L. I got both of them because I didnt know if your tranny came from a donar car with a 3.1 or a 3.4. I also got a diagram from a 1991 so you can compare and splice accordingly. Like I said, to me it sounds like a wiring problem because your car is defaulting to "limp-in" gear when in drive.

1991 Pontiac Grand Prix GTP 3.4L V6 4T60e Trans Wiring Diagram
1995 Pontiac Grand Prix GTP 3.4L V6 4T60e Trans Wiring Diagram
1995 Pontiac Grand Prix GTP 3.1L V6 4T60e Trans Wiring Diagram

[tblake]

BTW, after you click on the image, if you right click and click on Save image, you can save the picture to you computer and enlarge it to make it easier to read.

Good Luck! Let us know how it goes!

[kyledel]

Thanks a lot for the diagrams!

Both transmissions are from 3.4L engines and the tranny actually came with a motor so i just put the 95 motor in aswell as the tranny.

I checked out the diagrams and it turns out both tranny actually have totally diffrent wires going into them. Here is the list of the wiring someone please help me out here. Is it possible to cut and splice the wires to get everything to work?

91 transmission

A- Stop LT SW
B- 4th gear signal
C- 1st gear signal
D- Tcc signal
E- Ign fuse
F- Shift sol A
G- Shift sol B

95 transmission

A- 1-2 shift sol
B- 2-3 shift sol
C- Tcc pwm sol
D- Tcc sol
E- Tcc fuse (hot in run)
F- TFT sensor in.
G- Engine harness & OM from under hood electrical center breakout.


If anyone could tell me how to cut and splice the wires or if its even possible that would be amazing!

[tblake]

Originally Posted by kyledel

...I checked out the diagrams and it turns out both tranny actually have totally diffrent wires going into them

Thats what I was afraid of.

I'm no expert at wiring, especially wiring modifications. Maybe some one else can help you out. Another possible solution might be to get the engine wiring harness and PCM from the 95 doner car.

[kyledel]

the guy i bought the car and motor/tranny off of took the motor nd tranny out 2 years ago and scrapped the car so the harness is long gone =(

[tblake]

ahhh man!

Send a PM to Troy1, he's the GP tranny expert. He might be able to help you out.

[kyledel]

I sent a PM to troy1 but he never responded =( i dont suppose anyone else would know of a way to splice the wires so i can at least get overdrive working?