HELP!! Just tried putting the case back together and the crank is very tight - it seems the centre main when mated together has a gap of 0.88 mm at the end - indicating the crank journal is too big (!) or the bearing is too small - this is a standard and not oversize bearing so am I missing something here?
Part number on the original main halves are : 021 105 531 E - everything measured up to tolerances so have I been sold a duff set of mains (Mexican of course!!!)
I don't know if there is any history to the built elsewhere but how did you measure for the bearings?
Micrometer across the crank journals and inside the case halves - I've held the new and old halves against each other and the new one is actually larger by about 3/4mm - this would indicate it is for a case which has been machined out - but it is stamped as a "STD" bearing Have I got an "undersize" case?!?!
We're assuming here that your old bearings were the correct fit for crank and case, yes? You're just replacing them 'cause they're worn?