I had chased a similar issue a few years back. Thrust bearing kept getting eaten up by the crank in short order. Issue was a combo of trans and converter problems.

Trans had some wear issues that allowed pressures to push internals forward into engine/crank. Replaced most of the internal parts (front pump assembly, output shaft support, front clutch retainer) along with total trans rebuild. Then had the converter checked by Lenny and he found that the Dynamic 9.5 unit had in fact ballooned even with the anti-balloon plates. Lenny fixed my vert and provided a suggestion to make sure there was enough clearance/travel in the pilot hole in the crank and that the snout was not bottomed out. He even took a little hair cut off of the converter snout to help build in some clearance. Machine shop took a little out of the pilot hole to make sure it had some breathing room as well. This was on a factory steel crank.

It has been working fine after the fix and nothing in the filter on the last oil change.