I took mine apart a few months ago to check/replace the rear bearing on the input shaft. It turned out that I had the newer updated gear, but it was still eating into the bearing race. I faced off the gear on the lathe and turned the bearing around. I also replaced the wavy washer with a solid one, which should help stop the bearing race/gear wear, but makes the trans noisy at idle in neutral. I checked all the bearing and they seemed fine, so I put it all back together and all is well.
I say pull off the rear bearing on the input shaft. Its a fast and easy job if you have a press. Check the wear, if its not bad turn the bearing around so the good side of the race now hits the gear and put it all back together. As long as the bearings do now have to much axial play you should be good to go.