I am working on a 12/51 8N. The axels have been shortened to 26 7/16". I think the original axels were cut and re splined to get to that length. Before I started working on it, I rocked the rear wheels and had play of around 1/8-1/16". I could hear a "thunk" each time I rocked the wheels. I also lifted the rear wheels, turned one and the other turned in the opposite direction which I think is what should happen. I thought the bearings were bad but when I removed everything the bearings were in good shape. As you see the axels were touching at some point and have wear on the ends. There was only one metal shim on one side of the bearing retainer assembly. I will clean up the axel ends but I am wondering if I should add another shim, remove a shim or what? Thanks for the help. Gary