Okay guys, here's what I found. I double-checked the tranny and rear end fluid levels. Both are full, but when I pulled the rear end plug to check the level, I discovered nasty dirty chocolate-colored gear fluid and it is gritty to the touch. When I was doing the restoration, I had disconnected the driveline and covered the u-joint connection with a cloth (if I remember right). My truck was also missing the vent plug on the rear axle at that time. I sand-blasted the frame and I suspect I got a bunch of sand inside the axle by way of the vent plug hole. Would gritty fluid be sufficient to cause the grinding sound I'm describing? I suspect it could be. Regardless, I now need to fix this problem. Never having take a rear end apart or pulled the axles, I'm not sure what I'm getting into. I didn't pull the rear end cover, but I did drain the fluid before sand-blasting and I can't remember how I removed the fluid to do it. I also replaced the pinion seal when I had it all apart. I'm now wondering if I had the old seal off when I sandblasted. So, how do I go about cleaning this mess up? Suggestions? I haven't checked the shop manual yet. Does it sound likely I will need to pull the axles and dismantle everything to correct this problem? Thanks for the responses by the way. This is a 3/4 ton with the 8-hole rear lugs.
