901 bearing races...., How loose is too loose? Brad? Options

[bondo]

It's getting close to time to start taking apart transmissions so I can get at least one good one out of the bunch. I know there's been talk of loose bearing races in the case, but I don't know how tight they should be or how loose they can be before it's a problem. Is it a press in fit, or drop in with no noticable wiggle? Or do I need to measure it with some sort of expensive equipment? (all I have are digital calipers and a dial guage)

[silver2.0]

Your best bet is a micrometer and a telescoping gage. A good general rule of thumb for most bearings is .0005"+/-, depending on the bearing. If you have .001 clearance, a bearing will tap on with little resistance usually if the surface finish is good. Any less and you need to warm it up to at least 200 degrees F. .002" clearance, and the bearing will slide on by hand easily. You rarely have an interference fit of more than .0005, becuase the bearings start to bind, unless they are specifically designed for this purpose. Hope this gives you a few ideas.