Hi. I’ve started rebuilding my 1960 Dommie 99 engine. I’m at the stage of fitting the crankshaft into the crankcase halves.
I’ve got the recommended Superblend roller bearing in the drive side and plain ball bearing in the timing side.
The problem is that the timing side of the crankshaft is incredibly tight to fit. The Haynes manual says that it might require ‘a few gentle taps with a hide mallet’ to get the crankshaft to seat properly but I’ve just about destroyed my rubber mallet trying to get the crankshaft into the bearing. It goes on about 95% of the way but doesn’t seem to be seating fully home up to the bearing inner race - there’s a gap of about 15/32 between the face of the inner bearing race and the cheek on the crankshaft journal. That means that the joint faces of the crankcase halves don’t touch. Should I heat the bearing inner race to expand it, then drive the crankshaft into it?
Is there a pain-free way of fitting the crankshaft?
Anyone experienced this problem? Anyone got any ideas how I can get the crankshaft installed?
Thanks in advance.
Tony
Should not be that tight. J…
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Hi Robert. Got it sorted. I…
Hi Robert. Got it sorted. I removed the bearing from the timing side crankcase (lots of heat) and found that there was a small raised ‘dimple’ in the bottom of the bore where the outer race of the bearing is supposed to bottom out. I found a matching indent on the front face of the timing side crankcase. It looks like someone might have tried to use a small punch to loosen the bearing at some time.
I dressed down the small dimple to give a flat-bottomed bore once more. Then I heated the bearing and got it to fully fit on the crankshaft journal no problem - it just dropped on. The inner race has blued in one small spot but I think it’s ok.
Finally I heated the timing side crankcase and lowered the crankshaft plus bearing into it - the bearing went full depth very easily - no ‘persuading’ required. Crankcases are now bolted up looking good.
Regards
Tony
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Should not be that tight. J.H recommended that you polish the shaft with a strip of blue back emery bandolier fashion till the bearing is an easy fit .