Mentioned this in another thread but figured I should start a new one in case it might help someone else out too. Towards the end of last summer I began to notice a rumble/growl noise in my rear end (separate from the similar but much more aggressive noise I hear at partial throttle or when disengaging the clutch in 4HI). It's slowly become more common, and occurs when braking moderate to hard, accelerating hard and when accelerating around a corner. It was suggested that it could be any one or multiple of the bearings in the either the axle (stock semi float) or the diff. First step, I changed the diff oil when I got home from work today, and this pic is how it looked after just less than a year of use, using Schaeffer's 293 (which when new is a bright greenish yellow color). There was very little buildup on the magnet of the drain plug (small amount of film, but no chunks or anything overly concerning). All the bearings are original, so I suspect that suggestion is likely the case. Now my question is, which would be more likely to go first with age and use? I have been running 31" tires for more than half the truck's like (so not a big difference from stock) but went to wider, 33" tires last May. Is it likely this gave the outer bearings the final push to begin wearing faster and making noise? I'm hoping it's the outer bearings, since I really don't want to tackle a diff rebuild until I can get my hands on an FZJ80 rear and begin setting it up. Also I got the full amount of oil out so there has been none leaking past the (also original) seals, for what that's worth.
What're you guys' thoughts?
What're you guys' thoughts?