Cone diff?

[Cranky]

I do not know what grade of stainless it is.It was just a piece I found with the right thickness. It was austenitkind because there was no magnetism on it.
My theory is that some debris got in there and maybe because of that pushed the cone to hard.
I have polished surfice on the gear but marks on cone are to deep.

They usually do not wear evenly but are usually pretty close. Factory casting tolerances were not all that close either and the splines align them so they are not going anywhere but the splines do have some clearance and that allows the fretting. If debris got in there enough to make one cone wear faster, the debris most likely would have done other damage too and the fret marks in the cones is common. I'm thinking the shim stock you used might be kinda soft. Martinsitic is harder if I'm not mistaken. Give it a shot. You have a large surface area for it and it may be what 'Mom' should have done in the first place lol. I never did like cast iron against case hardened steel anyways and the SS shims may be just what it needs. Just make sure you don't bind the spiders and side gears with the use of the shims. If you do, it won't differentiate around corners.....ie, locked up like a spool and will be very hard on the gear teeth.