Well, since he had the transmission torn down, he coulda' installed an entire Sure Cure kit from Sonnax.
http://www.sonnax.com/system/instruc...4R100HD-IN.pdf

The kit addresses some factory shortcomings, and makes it a little more "tough" than a stocker.

It's what I'll be doing if mine ever has to come down.

Mind you, it isn't the same as having one of the "Top Two" 4R100 builders go through it, but should help prevent the trans from dying a premature death caused by a possible original design deficiency.

Pop