cone sure grip re build question

If you still have clearance, the cones have not yet bottomed out so just because you take some material off the face doesn't mean that you will end up having to shim that much. I usually don't shim them until the 2nd go around. Even with .010 to .016, it should still grab....but, if it were mine, I'd take off enough to get .035 clearance. The less you take off, the more material stays on the cone for lockup under power. I've never been able to find what the original thicknesses are on these but you also don't what your spiders and side gears to have full mesh with either because you could end up with a unit that's locked or worse, a cracked case however .025 on each side should be fine. The shims I've used are from Ford and run from .025 to .045 but have never had to use anything thicker than .030. Not sure if Ford still has these but the part # for the .025 is EOAZ-4A324-G, then H for .030, C for .035, D for .040 and F for .045.

As for the fretting between the side gear and the cone, I usually smooth the side gear out on a 10" grinding wheel that's laying flat on a bench. The metal builds up on the side gear from the cone and happens over time when the unit chatters. That's what is happening when you hear one of these thing make that chattering sound while turning. The cones are sticking and unsticking and makes these two parts play games with each other causing metal buildup.