Gears & Axles - driveshaft to safety loop interference




nubs4ck
08-20-2012, 11:07 AM
I posted a while back, I missed a shift and went from 3rd to 2nd (stupid stock shifter). I didn't damage the motor because i shifted at or below 4k rpms. The rear end started hopping around really bad and i noticed a bad vibration on acceleration. The vibration got worse very quickly. I did some investigation and found that the driveshaft is rubbing against the Spohn safety loop. There isn't much clearance but i never had a problem before. I got up under the car and can't see anything, there is probably a 1/4 inch clearance on top and maybe 1/2-3/4 on the bottom of the driveshaft. Can anyone think of what would cause this?

It appears as though the friction only occured on forward acceleration, it didn't seem to happen in reverse or deceleration but it is so bad now that I have to push the car forward. Transmission mount doesn't seem to be damaged, the drivers side motor mount may be damaged/broken, but they are poly mounts all the way around. Moser 12 bolt, T56, aluminum d/s.

What do the experts say?


nubs4ck
08-25-2012, 01:09 PM
I found the issue today. There are no bolt heads on the top of the pumpkin mount. I'm guessing that they sheared off. Anyone have any ideas on how to fix this easily? I don't want to have to remove my whole rear mount turbo setup.

guppymech
08-25-2012, 01:54 PM
Have you looked with a inspection mirror to see if the bolt heads are sheared off or if the bolts are missing. Moser 12 bolts have a problem with the torque arm mount bolts loosening up.


nubs4ck
08-25-2012, 02:01 PM
I just removed the torque arm and confirmed the bolt heads sheared off. Any ideas on how to get this fixed without taking the rear end out and drilling the bolts?

guppymech
08-25-2012, 02:21 PM
I'd take the rear end out so you can work on those bolts in the open. I changed out the rear in my car a couple times, working at a goof-off pace I can do the swap in 2-2.5 hours. It looks harder than it is. Just unbolt the rear caliper carriers from the backing plates and hang the calipers up with some wire, leave the brake lines connected.

Alternately, seeing how the heads are sheared off and there is no tension on them any more, I'd try soaking the bolts with some penetrating oil and try to unscrew them with a pick or something similar.