Right side main crank bearing fits perfectly in a steal outer ring. The outer ring seems to be cast into the right side case. Problem: this ring rotates about 30 degree, back and forth, and moves up and down, in the direction of piston travel a total of 0.018". This is bad Right? The engine runs great but has a tapping or banging noise. I bought this bike this way, my bad, it is a 96XT350 with 10Kmiles. It also needed piston, rings, pin, bore and valves lapped. Can I replace the right side case only? If I only replace the right side, what would be the biggest problem; leak oil???? Will the tramsmission all fit together properly? Has ANY one had a problem like this?