I never took apart the lower end of my 3W-100s, but Kris is correct. There is no detectable axial or radial play in the crankshaft when gripping the prop - hot or cold. I've also got over 600 flights on one and about 200 flights on the other. While we're talking about bearings, there should also be no detectable play in the rod needle bearings when you pull the piston straight up and down.