I "think" my front hubs are shot. I'm hearing bearing noise from the front when I roll. The D30 diff came out of a junkyard '89 so I don't know its' history but I've put 60K on a differential that could already have 200k on it. When I give the front tires a "shake test" for play however, the wheels seem rock solid. No movement. I suppose it could also be the front DS. What would you do as a next step? Misdiagnosis is an expensive pain in the _____.