The 10-bolt rear on my '97 Z71 has been "weeping" fluid out around the bolts and onto the cover/carrier for a while now. Is this to be expected after 40,000 miles? I'm going to change the fluid next week...any recommendations on a gasket?
I don't know if it's really expected, but it isn't really unexpected. As for gaskets, generally I just use RTV on my diff covers. Lay down a nice bead on the pig, let it sit for 10 minutes or so to "skin", then bolt the cover on. Make sure the old gasket is completely scraped off and clean both surfaces so they're free of oil before putting the RTV on. Also, make little circles around the bolt holes to make sure they it doesn't leak around them, and DON"T OVERTIGHTEN THE BOLTS. They're just holding the cover on, they don't need to be ultra tight, if they are it can cause the cover to warp and leak. Tighten the bolts down like you do lugnuts, that is, don't go in a circle around the diff, snug one, cross over to the opposite bolt, go back to the bolt next to the first bolt etc, etc. After they're all snugged up, then go back and tighten them. Yikes, that was a $10 answer to a $1 question[img]/wwwthreads_images/icons/shocked.gif[/img]!
10 bolts are famous for it. Look at any late model truck. Evan is right, RTV is the miracle cure, but everything it goes onto and seals has to be spotless!! I use it for timing covers, valve covers, diffs, even trannies every now and then.