Kevin in Atlanta

Can a '91 manual transmission, less the PSD be retrofitted to an 87 manual tranny?

FredR

As I understand you can but the installation would have no diff lock capability. Far better to modify the diff to a mechanical LSD as per the 89 box. I believe this is possible from research I did some time ago but defer to those more knowledgeable.

Regards

Fred

Rob Edwards

The input shaft bearing is the same between '87 and '91, as are all the gears. The only difference is the ring and pinion, of course. I ASSume you can mount a '91 PSD ring gear on an earlier LSD diff carrier, but don't know for sure.

Why not just swap an LSD into the '91GT transmission? The zombie has a standard LSD installed in a GTS box.

Table of gear part#'s by tranny model:

Kevin in Atlanta

I guess I could have phrased the query better - can I mate the front of the 91 to the 87 diff?

Rob Edwards

This would be a lot easier if we were all sitting around a bar, somewhere...

I still don't understand- Take the '91 tranny and mount an '87 diff into it, transferring the pinion gear from the '91 onto the '87 diff carrier? (AKA transplant an '87 diff into a '91GT transmission?)

If so, the answer is (99% sure) yes.

James Bailey

The 5 speeds are a single case not two part like the automatic.
But the internals will fit. As Rob pointed out you can put the earlier differential /ring gear carrier into the PSD box. Or run the PSD with no limited slip functioning but it is less than ideal.

Kevin in Atlanta

Thanks Jim - Now I understand.