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Discussion Starter #1
Thanks for all the responses to my rear diff questions last month. I bought a used diff and slammed it in the MoneyPit. Not toooooo difficult with a transmission jack. I installed new bearings in the rear hubs while I was there. I packed those bearings like crazy with red high temp grease. However, I forgot pour diff lube into the space between the inner and outer bearing as recommended in the service manual. Sealed her all up and put lube in the diff along with too much limited slip juice and drove it for about 100 miles. Serviced the diff on Saturday after the oil cooler flush. Put in a little over 3 quarts of Royal Purple. There was a little smegma on the plug magnet, but not too bad. However, I have a faint little whine. It seems to be on acceleration. It sounds a little like a gear drive unit on a hotrod. Should I pull the axles and add some fluid. I just assumed that the fluid would find its way into that hub housing. I further assumed that the amount grease that I packed in there would hold the bearings until some fluid found its way out there. The whine is VERY disappointing given the amount of work that I did, but that is the crap shoot of buying used parts. It saved me about $600 at the time, but it might end up at breakeven, and in the hole as far a my time goes.
 

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Discussion Starter #3
For sure it could be the used rear. My curiosity is, could it be the lack of diff fluid in the hub housing. The service manual recommends adding a couple of ounces of fluid to the hub housing. I forgot this step. I just figured packing the bearings would hold them until fluid got there. I don’t really think it is wheel bearings, as the slight while is only on accel. I am probably going to let it rock on for a bit, as there was not too much in the plug magnet so I don’t think anything is about to catastrophically fail. As I mentioned used parts are a crap shoot. I just figured it was pretty good odds on an item that does not go out much considering the miles on it.
 

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Put the tranny in neutral and
Jiggle check the pinion bearings -- one that has been sitting a while could have rusted the bearings
and since you have ran it they may have become rough or loose

Bevel gear fit is where gear whine comes from -- running a gear set with loose bearings or a wrong gear clearance can cause permanent damage to the gear tooth faces and make the noise difficult at best to lessen

The axle hub bearings do not turn fast enough to make a noise (would be more of a rumble) and since you greased them should not be a problem
unless they are over tight or too loose -- I have seen some really bad information on the bearing pre-load
 
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