Diff brg size?

[Chuck Leeper]

Am about to put a Tru Trac in the T.
Looking at the Summit site, I see this notice:
8.5/8.6 in. Eaton differentials require special bearings. For axles with small bearing bores (race O.D. of 2.89 in.), usually found on vehicles prior to 1999, bearing LM102949 and race LM102911 are required. For axles with large bearing bores (race O.D. of 3.06 in.), usually found on vehicles from 1999 to present, bearing LM603049 and race LM603012 are required.
I've not had 1 apart for many yrs, and don't remember large, or small brgs?
In a search, I see reference to "oversize" brgs being needed..Y/N??
Want to get it all together, B4 I tear it down...

 

[pacecarta]

you need the bearings for the center your installing ..the true trac most likely uses the larger inside diameter eaton bearing aka spool bearing for 8.5 rear
the outside diameter of the race doesnt change with center swap so it needs to be the earlier (smaller ) for 8.5" rear ..not the newer 8.6" (which is the same outer diameter as GM 12bolt and ford 9" )