glhracing

So i have a 1983 5 speed that failed. I found a 1979 gearbox for cheap money.
What i have unfortunately discovered is that the sleeve on the box that receives the TT shaft on the front of the transmission, "5th gear" with the pinch block is shorter than on the 1983 gearbox.
What this now means is, when you attach the drive shaft, it pulls the shaft back further. So up front, where the TT shaft meets up with the clutch drive shaft, the gap is now too big and the pinch bolt coupler no longer lines up. essentially the overall length between the flywheel center bearing to the pinch bolt on the front of the gearbox is about 3/4 of an inch longer. The front clamping sleeve no longer fits.

Anyone ever run into this?
where can i find a 1979 front coupler, and be sure it is the right length ?
are there any after market pinch couplers available where the length can be adjusted.?

Thanks,
-Brian

Richard S

Transmission was changed in mid 1980.

I think the torque tube/central shaft was also changed.....which means you would need the early (78 to mid 80) torque tube/central shaft to go with your early transmission. Hopefully someone else can verify this.....

Rich

Mrmerlin

Rich has it right you need the early TT with drive shaft
IIRC the early part is longer by 24MM

Dave928S

I'll second that ... TT and shaft lengths are different ... you'll need the early TT.

glhracing

Hey Guys,
Thank you very much. After some serious digging around i found this link:
https://rennlist.com/forums/928/3850...d-tools-6.html
Erkka, explains it very well. Great link if you are looking to rebuild the TT also.
The Guys at 928Worldwide are going to set me up with the right TT.
Always an adventure..
-Brian

glhracing

Just for sanity sake.. when using the 79 TT with a 79 box.. the trans mount bolt holes will line up with the 83 rear sub frame bolt holes correctly.... Correct ??
I think my head will explode if not.
B~

Mike Simard

No, it's not going to line up. With the proper TT your trans will be sitting backward of the crossmember by 30mm IIRC.

glhracing

Thanks Mike,
Did you make custom mounts for the trans.. or did you just make a bracket for the crossmember itself?
Its Conceivable i could bolt a wedge of steel to the cross member and then bolt the trans to those. May have to tie the two sides together in one U shaped piece to give some strength and avoid any twist. I dunno.. may just have to wait and see once its in place.
All ideas are welcome.
Thanks,
-Brian

Mike Simard

I was wrong, it's actually 30mm further back for you.
Usually folks swap in a later trans in an early car. I don't think you have any alternative to getting an early crossmemember to match your TT.

FYI the mounting holes and distance to TT is that same on all transaxles. They were basically moved forward in '80 by way of a shorter TT. It is better because the axles are in less bind. You're going the other way though. hmm...

Mike Simard

Here are some pics. This is putting a late box in a 79 crossmember which is moving things the opposite direction from yours but it gives you an idea.
Notice the inner mounting ears on the pic below, yours will be poking forward noticeably.
The trans pic shows the mounts I made.

Vilhuer

There are three different versions of early TT. Only 3rd will have mounting for selector arm on top of TT. Earlier two use body to support it. Also rear selector arm is longer in early cars.

I would simply find G28/05 or later gearbox instead of finding all needed parts to use G28/03.