Overheard an old-timer say something about bearing clearances that got me thinking

I was grabbing parts at the supply house Tuesday and this guy in his 60s was telling the counter kid that most new mechanics set their guide shoe bearings too tight. He said he always leaves a .015 gap on the inside because the rail heat expands things. I never really thought about that specific number. Has anyone else heard this or got a rule of thumb they use for bearing clearance?

3 comments

3 Comments

evan5438d ago

@pat_murray53 a dime is actually .053 but that .015 rule works for me on long runs.

charles_baker288d agoMost Upvoted

That .015 gap sounds about right honestly. I've always shot for a dime's width on the inside (you know, like 12-16 thou) for guide shoes. Rail heat is real especially on a long run, I've seen stuff bind up tight when it's been running for an hour.

pat_murray538d ago

Is it possible that dime width is closer to .045 than 12-16 thou? @charles_baker28 I mean a dime is like 10 cents thick but that's way bigger than bearing clearance usually. I've always gone closer to a playing card or .010 for stuff that sees heat.