LongDuck

Have a slow seep of 90w coming out of the 3rd member and planning to remove the pumpkin out the front with the axle still in the car, if possible. Replacing the driveshaft due to bad front U-joint and figured I do this at the same time while the driveline is out. Any tips or tricks on getting a good reseal?

I plan to put the rear tires on ramps to help keep the 90w in the transmission when I pull out the tailshaft, but aside from that I've not had to do anything to the rear end other than new upper & lower arms and Watts links after 225k miles. This being an -SE, I'll end up replacing the 90w in the rear along with the GM LSD additive. Hopefully this will quite down the ride again, as it's developed a lot of noise from the U-joints. TIA,

GSLSEforme

You can do this job as you describe with axle housing in car but you will need to support rear of car on stands as tires,brakes,axles must be removed from housing to enable 3rd member to be removed from housing

You can remove axles just far enough to disengage splines from carrier and leave them in the tube as some do. I prefer to pull them all the way out as i've had some develop oil seeping from axle seals afterwards as the weight of outboard axle end with bearing,retainer,backing plate tend to stretch or even displace seal tension spring in back of seal. Now is a good time to renew axle bearings and seals as they're already out. As i recall your car has some miles on it,probably has had this done at least once.

After removing all the attaching hardware you'll want to wack the pumpkin from side to side with a plastic hammer or mallet or block of wood to break its seal from housing and then wiggle it out. Clean up sealing surface of old sealer remnants with a razor bladed followed by a wipe down of housing and 3rd member with a rag with carb cleaner or brakleen on it to remove all traces of oil and old sealer. Gray permatex RTV for gear oil is what you want to use,with your finger apply an even not very thick bead around sealing surface of axle housing just enough to leave a small even bead of sealer on outside edge of pumpkin as 3rd member is tightened in place. You can wipe this off and clean up with brakleen on a rag. I leave it in place as if/when there is a leak in the future you will be able to see the drip forming on the bead of sealer.
Put the 3rd member back into housing as straight/square as you can. Some pumpkin/housings are a very snug fit and easy to get cocked part way in. When lined up well straight and mostly in to where you can install all retaining hardware,put a block of wood on companion flange and tap pumpkin home.

Now is a good time to renew output shaft seal in end of trans.

LongDuck

Thanks for the note, man - that's exactly the kind of reply I was looking for. Waiting on parts right now,