Let\'s play- NAME THAT GASKET!***UPDATE!*** Okay, long story short, my nasty jake brake noise is NOT an out of round driveshaft. Guess what it is? give up- okay I'm going to try to explain this without knowing the proper terms, so bear with me. The driveshaft, connects to some Knuckle thing, before going into the rear axle- that knuckle thing....where it bolts on, the bolt is loose, and when I say loose, I mean LOOSE! With the truck in neutral, it moves I'd say 1/2 inch. At the same time as it's moving, - its LEAKING....the rear axle that is.. So, not only do I need to take the driveshaft off to get the bolt tight, I also need to replace that gasket, its in the open after this point anyway- so why not. When I go to the useless parts store tomorrow- I haven't a clue what to tell them...other than I know the axle came from a 76-77-78ish, full size pick-up. I will be bringing in the old one with me, if I can get the driveshaft off in the morning. but, whats the gasket called? or more yet, whats the name of the thing its "gasketting?" thanks Brandy see bottom post for update!