Bearing Shim question

Flathead

Well-known member
I am checking clearances on my 1930 A. The pan has not been off in a long time judging by the crud on the outside of it. The rear main has shims that are .003 each. The clearance would be good if I left only one shim (.003) on one side of the cap. I don't have any thinner shims, is it OK to just have a shim on one side only? I figure I'm lucky to have any shims left at all.
 
It is OK to remove a shim from one side to get the clearance you need.Measure both shim packs & if one is thicker than the other,then remove one from the thick side. When checking brgs,I fold a piece of alum foil until it is .002 thick & place it in side the cap & tighten it up.If the crank shaft binds up,then you know the brg adj is OK with foil removed.
 
On my 1949 Chevy truck with a 216 the Motor's manual said which side should have the thicker shim pack, if they were uneven. They didn't say why it was prefered to be on one side, and I don't recall which side was prefered. I've never heard the same recommendation about the Model A engine though, so I'd guess it won't matter as long as they are as close as possible on each side.
 
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