i recently purchased a 91 yota 4cyl auto 4wd and noticed it had a roaring/whining noise from about 40 mph and up...really noticable at 60 mph...i decided to change the differential oil yesterday and found lots of metal shavings, a few small pieces of metal and the old oil was really thick...it is still roaring after the oil change...am i in need of a new rear diff? if so, would it be cheaper to just find one in a junk yard rather than having my current one rebuild?
thanks for any input
later,
Josh

 

Cheaper to get a used one. The V6 ones are stronger. Just make sure you get the same ratio as the front. When we bought our 85 it had a bad rear, we just changed it out.

Be sure to clean out the housing so the new/used diff doesn't get chewed up by the debris. We filled a sprayer bottle with ATF to wash out the crap. Also a magnet to attract the steel chips/flakes.

 

Used diffs can be found pretty cheap on various forums. Try looking in the for sale section of this board, 4x4wire.com and pirate4x4.com