I have a completely rebuilt 9" traction lock. All new bearings, spider gears, side gears, clutches etc. It's a Richmond Gear "excel" 3.50 set.
I used Ken's awesome video for the build up and thought I had everything right but when I took it for the first 10 mile cruise I had a decent howl when coasting and when I got back the rear of the housing was pretty warm to the lay your hand on. The BL marked on the ring gear was .008 and I checked 3 places and got .008 to .010, and the pattern looked good. Should I pull it back out and recheck things before putting any more miles on it or continue with breaking it in?
I bet you have the carrier bearings adjusted too tight. That will cause the heat and will destroy the new bearings.
I know from experience!