DIYbanter - View Single Post

Terry Coombs[_2_]

wrote:
On Saturday, January 3, 2015 6:41:38 PM UTC-5, Terry Coombs wrote:

. Dan , I have a bearing race
that's pressed into a hole in a Harley 3 speed case . That race was
perfectly fitted to the clutch gear before I pressed it into the
case . Now it's out of round ... thus the need to lap the race . I'm
wondering if it's worth the trouble of peressing it back out to
check the hole and the race . Might be that the race is perfect and
the hole is out of round , might be variations in the thickness of
the race . Either way it's unacceptable as-is with OOR .0015" total
Should I decide to lap it in place , what material do you suggest
for the lap ? I have on hand lead , wheel weight material , aluminum
, and several grades of steel . I can cast anything but the steel
directly onto a mandrel for machining to maintain concentricity - I
will be using a guide bushing on the other side of the case to
maintain alignment . I started an adjustable lap set several years
ago , but it never really worked out like I wanted . I did learn a
lot though ! --
Snag

I would press the race out of the housing. The race is not likely to
have been out of round or have variations in the thickness. So I
suspect the hole is not round.

I am not an expert on laps and lapping. What I read is that the lap
must be softer than the metal being lapped. That is so the abrasive
embeds in the lap and cuts the metal. So what is the Harley case
made of? I suspect aluminum so you would want something softer than
aluminum. So lead or wheel weight material. I think most wheel
weights are now Zinc and could be too hard. That assumes you are
lapping the hole and not the race. If you lap the hole , you may
need to use locktite compound when you put the race back in. I am
pretty sure they have a compound for seating bearings. yes, they
have several retaining compounds.

Dan

If I modify the case it'll be with a boring head . I hadn't considered
using a retaining compound . I was just thinking about the forces involved -
this bearing is also the main thrust bearing for the clutch - and that may
be the correct solution . I'll be loading up the bike and bringing it home
from Memphis in the next few weeks . I have a very few pieces here because I
haven't had storage space . That is about to change , the time has come to
get this machine back on the road .

--
Snag