josephsc

So I finally got around to installing my replacement transmission -- it's from an 88 S (with LSD) going on an 87na chassis.

Only a couple of minor setbacks -- I had to dremel thin the gear selector to get the damn short shift kit to fit. And I now have a small oil leak due to a hairline crack -- we dropped the tranny to the ground at one point when we were removing it from the donor car... I guess I'll have to do some welding later.

The real question I have is the following: the tranny won't mate to the torque tube properly. The bellhousings are flush up against each other, and the torque tube coupler is on both the tranny input shaft and the torque tube. But I can only get one of the two locking bolts on the coupler to go in. These are the bolts that have to line up with the 'key hole' in the tubes for proper fit. It is as if the torque tube coupler is 2mm too short -- or the torque tube needs to be pushed back 2mm (while the housing remains in place).

Has anyone encountered such a problem before?

Also, is it relatively safe to just say forget it and run only one bolt on the coupler?

User 41221

No, its not... keep working at it, you will get it.

Out of curiousity, you do know that running a 951 tranny in an NA is a receipe for massive amounts of frustration, right? The gearing is not at all favorable for the NA< if you thought the car was slow off the line before...

I'm calling first dibs on your 951 tranny if you decide to replace it with a NA one...

Regards,

nine-44

Make sure that the top bolts are up tight. I had a few that the guide dowel pins in the top two bolt holes pulled out with the trans, sometimes you end up with two dowels on one hole. Thus, it won't pull down all the way. I guess it is possible that if the trans falure was bad enough, it may have pushed the TT shaft foreward. It's not very likely tho, there's like 3 or 4 pressed bearings that hold it. I wouldn't run without the bolt either. Loosen the other bolt but leave it in and see if you can position it good enough to get the second bolt in. I use a large screwdriver or prybar to slide the sleeve. Good luck.

marky522

the shaft will slide back and forth in there, get a pry bar and gently pry the shaft the direction you need it to go, it shouldnt be too hard to move.

Mark

josephsc

Well, sounds like I'm headed back under the car with a pry bar.... Darn it.... I did make sure that the top bolts were in completely -- it wasn't the first time so the bellhousings weren't completely up against each other, but the second time was good.

Scott, just to make everything confusing, I'm mounting a 944S tranny (rather than the turbo S tranny) -- which had gearing not too different from the 944na (nice and short). But it's going on an 87na with a 968 engine -- so it's actually little too short for everyday driving. That's okay, I like my everyday driving to be rather "brisk", but then that's how I killed the earlier tranny.

Laust Pedersen

Danno and I swapped my white 1987 951’s LSD transmission into my black 1988 951 and we had exactly the same problem, but maybe by ¼”.
Mount the coupler (insert and tighten the bolt) on the torque tube shaft only, get a suitable pray bar and use the coupler flange to move the shaft. It took more than “gentle effort” to move it in my case.

josephsc

Thanks for the suggestions -- I guess I'll have to recoupe some strength and get back at it with a pry bar in the morning. Funny how the pry bar is the most frequently used tool when it comes to tranny remove/install.

I couldn't wait, so I did do a quick test run -- not smart, I know -- but holds up okay for a brief run upto 80mph and 4000rpm.

Dave951M

Ditto on the pry bar- the driveshaft can be moved for and aft within the tube. Some move easier than others. This isn't a huge problem.