A little history first.
Truck has d-70 with 140,000 miles on it

Replaced pinion bearings 5000 miles ago, front bearing went out. When I replace bearings found I had 4 thousandths play and had to remove shims and every thing has been fine then I noticed a slight squeak sound when I rolled down the drivers window and only heard it at low speed and confirmed when walking next to truck . it was coming from the drivers rear wheel. Pulled it apart today and found that the inner bearing looked fine but would not roll (had flat spots on some rollers and slight scuff marks on the race) so I replace with new. I also took off the rear cover to inspect diff. and put new Hitech cover on with synthetic oil. Very little metal flakes were found and almost nothing but clutch material on magnet. Seems OK and no play.

I put the truck back together and test drive and the &#&?** truck still squeaks .

Any I deals on what to check? Maybe spider gears? or what. HELP

 

Get rear wheels off ground (safety first) and let it idle with wheels turning. Now you can get closer and listen carefully for location.
I might be no more that a brake shoe rubbing or U-joint protesting.

 

Only does it going up or down hill at a slow speed. I may try loading it with the parking brake. Is there any thing in the diff that can make a creaking noise at slow speed in a straight line?