Hello! I have a 1989 LX 5.0 Auto with 3.73 gears and that is all. Anyways, I have a loud noise coming from my rear end during light-medium acceleration in all gears at all speeds, however it goes away around 65mph or so. Very little noise during deceleration. The noise goes away when off the throttle and returns when back on the throttle. No noticeable noise during hard acceleration at any speed. It sounds very much like a machine lathe if you have ever heard one? lol. Anyways, Im just wondering if this could be a back lash issue or a trac-loc issue? Idk, but I have replaced the passenger side axle shaft due to some pitting, axle bearings and replaced the diff fluid(I didnt notice anything while I had the cover off) Any ideas? Thanks guys!

 

Yes, I did a search