Just brought home a 92 RS anniversary project. Originally a V6, but PO hacked in a 305,

After getting the 305 running we went to pull the engine to access the subframe that was hacked in order to fit the wrong headers, which BTW, will never fit in the hole.
We raised the car on a two post lift-
We originally wanted to drop the transmission first, but not being familiar with the whole torque arm concept, we removed the torque arm bolts from the diff and the entire rear rotated instantaneously, creating quite a pucker factor for a moment . I checked a video or two on line referencing torque arm removal and they didn’t have this issue. I assume it’s because they had the driveshaft installed, which we did not?
We ended up jacking the diff back into position and just pulling the engine.
So… if we want to drop the transmission I assume we need to block up the pinion again the floor to prevent the dramatic droop? Is that how you Gen3 gurus do it?

 

Axle rotates because the springs are pushing down on perches behind the axle tube. It's no big deal if it rotates but it can make it a little challenging to reinstall the torque arm.

I would just leave the torque arm attached to the axle if possible. It still will rotate up but only as far as when the torque arm bumps into the floor pan. And you can pull it down with one finger at the end of the torque arm versus needing a jack back at the pumpkin. But there's no right way or wrong way, just do what works for you.

 

Just FYI -- the travel limits of the shocks are the only thing limiting the droop of the axle. Don't disconnect the shocks without the axle supported.

 

Actually, then the limiter will be the brake line.... for a while....

 

As said, the rear tends to rotate, because the springs push on something that's not on the axle center. Furthermore, if it's left hanging, then neither the force of the springs, nor the stops that keep it from falling out (the travel limit of the shock absorbers), are centered.

It's very eeeeeezzzzy to overcome however. Raise the chassis until the rear hangs freely; put a floor jack under the pumpkin (center casting of the rear); raise it just barely enough to move it off of the limit of the shocks; and place jackstands under the axle tubes. The axle tubes ONLY. Not the pumpkin, not the shock brackets, not the spring perches, NOT NOT NOT NOT NOT NOT NOT. Under the axle tubes ONLY. Supporting the rear this way minimizes all the forces tending to rotate the axle. Once you bolt the TA back to the rear, you'll be able to move the transmission end of it up and down with one finger, as also said.

The drive shaft is totally irrelevant.