Topic: This doesn't look good
in Forum: C3 Driveline Components
I had to change mine out last year after it (rear U-joint) sheared and destroyed the rear input shaft, battery box, and other pieces. It also helps to have two of you under the car so one can use a light and help guide the wrench onto the bolt while the other snakes it in.
You will need a 12-point socket for the 4 bolts on the bracket holding the u-joint in. It should be the same as the front, although mine weren't. I can't remember what it was but I think it was a 10mm or there abouts.
A really long screwdriver also helps for popping the u-joint out of it's holder.
Good Luck!
Lifetime MemberModerator
Usually, if the u-joint is slinging grease, it's because someone pumped too much in it while servicing. Of course, if your's doesn't have grease zerks, then that wouldn't be the case!
Joel Adams
C3VR Lifetime Member #56 
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"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
Thanks Joel, after looking again, I think its going to be the seal and not the universal. Dennis, Im looking in my tool box for one of the hookie thingies, I know there is one in there somewhere 
Lifetime Member. Jimmy B.
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starting with '80, GM changed the diffs just as you said. That bracket that bolted onto the older cars was now cast into or part of the diff. housing itself. Thats why 1980-82 are listed differently then the rest in catiloges, etc.. What worked the best for me was, 1st- get the rearend off the ground. enough so to be able to both spin wheels/ shaft freely, and have room to work. I made full lenght ramps that I drive up on that gets the car off the ground, front and back, enough to work under it using a creeper. 2nd, I use 1/4" drive, 12pt., socket w/ long extention. I don't think I had to use a univeral, but I'd have one handy just in case. I was able to undo one side of the U-joint, then rotate 180 degrees and undo the other side. once undone, slide shaft forward, clear rear flange and pull back out of tranny, remove shaft. And I didnt have to drop the exhaust get it out, but thats on an '81... yours may be different. Hope thats of some help. Jimmy (aceinthehole) I know has done a lot of work on one of his (vettes) in that area.