Mission accomplished! My car does have posi, it has one of those tags on the filler bolt. I only questioned it 'cause I've read where some guys said they didn't have posi's on their cars. I now see why the guy at the quickie lube place had a problem getting it off, it has an allen head instead of the universal 3/8" hole in it. The guy spent about 20 minutes on it and said "Aw caint git it off, it must be wallered out" I guess I'm good to go now, a quick meal with the maternal unit, then off to Daytona Beach for the Turkey Run...woo hoo!

Jeremy, It's much easier. You cannot drain all of the diff fluid with a syphon! You can't get to the bottom. You also don't have to touch the tire carrier. Back onto a set of ramps, remove one of the mounting bolts from the bottom of the case, )the front bolts will be lower- the rear is on the ramps), drill a 1/4 in. hole through the bottom of the bolt hole. It gets a little messy when you punch through as you are drilling into the diff oil. All of the oil will drain out. Coat the threads with a sealant (silicon...) before you put the mounting bolt back in, it will not leak and you now have a way to change the diff fluid whenever you want. Use the GM Posi-Slip additive, it's the best. You will be surprised at how much new lube will help. The whole job won't take 20minutes...john

Thanks guys,

Mission accomplished! I managed to squeezed the bolt off with a stubby wrench and a body hammer in the round side to give me some extra pulling. The corners of the bolt were a little rounded so no ratchets would get it.

I used one of those pumps and sucked all the old stinky oil out. It was black as mollasses, no metal pieces though! I poured in the fluids and voila! No more crunching.

It is pretty bizarre, the car feels more stable back there now. I guess the sticking clutches cause some minute vibrations. Or maybe it is just in my head.

Thanks for all your help, next time will be a breeze! Now on to other matters because as you all know, with a 30 year old car, there always are!!