Grinding noise
 

I recently discovered a grinding noise in the rear end of my truck so I did some investigations. I pulled both axles out along with the bearings and everything. I blocked up the rear end and put it in gear and it still grinds... Do I need a new rear diff? The bearings on the driveshaft look good. It's sort of grinding groaning noise.

You might want to pull the diff cover and have a look.