quote:My initial question was will i get myself into trouble removing the side cover to inspect the bearing. Could an out of balance half shaft wear the bearing in 3k miles. The manual is pretty vague on this process. I'm afraid of pullin the cover and something falling into the case requiring removal and teardown of the whole unit.
No, removing the side cover won't cause trouble 'cause everything is snap-ringed together as an assembly. As long as you reassemble the side cover with a real ZF gasket (or reuse an undamaged OEM gasket), and don't mix up the shims that are inside the side cover under the snap-rings, the tapered bearing preload will be identical to what you had before. The only possible problem may come from the shim-washers that are between the side cover and the bottom cover, on the two long external tie-bolts. If you leave the shim washers out or mix them up with something else, when reassembling and torquing the long bolts, you can bend or crack iron side covers.
Note the inboard halfshafts do NOT run in tapered roller bearings. Each inboard stub axle runs in its own ball bearing and splines into the differential innards. The tapered roller bearings only support the differential. I suppose it's possible one stub axle could be worn a bit or the ball bearing & axle are victims of a tolerance mismatch, causing a tiny wobble that doesn't cause a lube leak. A missing snap-ring might also allow a small wobble. But unless you hear a grinding noise typical of a damaged ball bearing and find lots of steel in the magnetic drain plug, there's no reason to think an axle-support ball bearing wore out. It's far harder than the inboard stub axle surface. I hope you have a good set of snap-ring pliers 'cause some of the side-cover snap-rings are very large and very stiff!