BSA Owners' Club Workshop Discussions

The BSA Workshop => Singles => Topic started by: EDDIE SIMPSON on 28 Sep, 2020, 21:29

Title: b31 crankshaft re assembly help wanted
Post by: EDDIE SIMPSON on 28 Sep, 2020, 21:29
hello b31 experts. i have a shim fitted under the smaller crank ball bearing. its worn but i cant see it on the drawings. can it be a shim? and does anything like a seal fit in the crank recess?
Title: Re: b31 crankshaft re assembly help wanted
Post by: EDDIE SIMPSON on 28 Sep, 2020, 23:57
I found it in a previous post 66 0661. it is a shim but not on the crankcase drawing
Title: Re: b31 crankshaft re assembly help wanted
Post by: Pete C on 29 Sep, 2020, 06:05
In my parts book it also 66-661 - engine shaft shim. Why it's called a shim I don't know it just appears to sit in the recess and not contact the bearing at all, maybe it is supposed to retain oil. There are other shims to align the cush-drive if necessary but these do not contact this "shim". Anyone else got ideas?
There is no seal between the crankcase and primary but if you have are replacing the main bearings then I use one with a rubber seal on the outside to reduce the risk of flooding the primary if it gets a bad case of wet sumping.

Cheers
Pete