under size bearings question

[lightnin-boy]

when your looking to replace bearings, if old ones are for a undersize crank are they marked on the back of the shells? I'm trying to determine if my crank has been turned and want to order the correct bearings.

Thanks,
Kirk

 

[gtm1086]

Micrometer the only true way to know the true measurement

 

[JOHN G]

I have never trusted any markings I have found-measure twice and then measure again.

 

[The Plankster Prankster]

undersize bearings are USUALLY marked with 010 or 020 to identify the undersize, i would say that if your bearings are unmarked, MEASURE, and if they're marked, the mark is probably right but it's still best to measure

 

[mustangsilly]

While mic'ing is always a good idea, bearing shells will be marked with whatever undersize they are. The critical thing is "is the undersize correct for the diameter of the crank?"

Just as an aside, crank kits come with the undersize bearing matched to the crank, so if a kit was ever put in, the bearing would show you how much the replacement crank was turned.

 

[addo]

Don't know about there, but here a crank grinder will engrave the crank with details and date.

 

[lightnin-boy]

Thanks guys!

Kirk

 

[fmartin_gila]

Also check all the throws. I once did a jeep engine in a hurry with .010 undersize bearings and had a noise. Took it down and found one of the journals was .020. It pays to be thorough.
Fred