225 51U, still fighting track binding. Final drive assessment ideas

I think I am still trying to swallow the high probability I have a final drive issue. As I posted a while back, one track binds up and stalls when tracking with anything more than a slow crawl. The chain stretch was determined to be in spec, though worn, and bushings are not striking the tips of sprocket teeth.

We knew the track brake was leaking bad into the final and drive motor was not tight which allowed water in the final and the motor was then hanging on the input shaft and bearing thus totally destroying the input bearing and cracked the input shaft. I really thought when I found the bearing failure, I found the problem and it was a super simple repair as the input hub comes right out and was rebuilt.

Well, with a rebuilt brake and input drive, the problems remain.

Before repairs of the brake and input shaft, the final oil was drained and inspected. There was nothing more on the magnet but normal gray matter you would expect. No chucks, no filings. However, it was obvious water was in there. I did an inspection just as good as I could looking into the final and the gears looked nice. However, I cannot help but think a bearing was trashed. I REALLY hope I am wrong here. Any ideas how to assess this issue on the quick an easy? I realize a full teardown of the final is the right way but I realized this final requires the entire final be removed from the carbody. This is going to be MUCH more than an adventure.

I am desperate to use the machine and considered just crawling at snail pace until I can figure this out, but I also kind of want to know what is going on. I know those tapered roller bearings can take some abuse but I suppose in an application like this, any play in the bearing may cause massive problems in backlash in the gear mesh?