> Unless someone can bring new information to the table, I think my
> options are
> to pick either .003" which is too tight or .008" which is too loose.
Get some fairly fine sandpaper (300 wet or dry should do, use it wet), lay
it on a flat surface (MDF or a sheet of glass) and dress down the oversize
thrust washers by .001". It will only take a few seconds, as they are very
soft. ISTR this is even described in the TR2/3 service manual.
> I understand that this is a real weakness in the TR4 engines so I
> want to get it right.
It's actually not a weakness in the TR4 engine ... the problem is with the
TR250-6 engine which has only half as much thrust surface as the TR2-4
engine. The 6 pot is also known for letting the washers fall out of place
when they're well worn, but I've never heard of that happening with the
TRactor motor.
You could probably "get away" with either the .003" or the .008" ... the
danger with going too tight is that thermal expansion may remove all the
clearance which would make the bearings overheat and weld, while the larger
clearance allows the crank to bang into the washers every time you depress
the clutch, which will shorten their life somewhat. But since it's so easy
to do right ...
Randall
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