Re: Rear End Howl '96 Bronco
While it could well be the gear set, I find it more likely that a bearing is worn, possibly a pinion or differential. Doesn't really matter though since everything would have to be replaced for a rebuild. If you are concerned about the ring, pinion, or limited slip I recommend taking the cover off, cleaning everything, and replacing the fluid and the FRICTION MODIFIER. The friction modifier is what allows the clutches in the L/S work properly. Generally, a malfunctioning L/S causes a chattering noise rather than a howl, or it simply makes no noise and doesn't work at all. While cleaning the differential, you might apply some marking compound to the ring gear and check the pattern where the gears mesch. That might be a moot effort though.