How to rebuild a 8 3/4 Borg Warner Posi Unit

the clutch less differential is actually very simple to rebuild once you dissemble the carrier you will find the cone "clutch" steel cone with spiral cut into it measure the overall thickness machine the flat face of the cone "so it can sit lower in the carrier" remeasure the overall thickness add shim to back side to keep overall thickness the same " pinion shims work perfect I think i used 10.5 ford. If you have access to a brake lathe it works perfect for machining the cones. I add a little extra shim to take the excess slop out of the spiders but don't run them tight it will act like a spool!