RE: (ET) Mower motor bearings

["Elie, Larry (L.D.)" <lelie ford com>]

Good point.  A couple of other points may be in order as well...

I have had to do re-heats as well; some times things are just real 
bad.  You don't want to over heat the armature, yet the 'best' 
method for a really tight shaft is to heat the SHAFT, which expands, 
stretching the bearing inner race then quench the whole thing.  After 
cooling, heat just the inner race, expanding it more or less 
independently of the shaft.  If the thing isn't too stuck, you can 
skip the expand the shaft to stretch the race part.  In either case, 
you still have to pull the bearing.

The other problem is that, on occasion, if the puller only grabs the 
outer race, the bearing comes apart.  If so, you have to do it 
again and just grab the inner race.  Oh yeah, and I have seen 
the shaft mushroomed (someone who overheated the shaft?) so that it 
had to be touched with a die-grinder to get the bearing off, and 
then turned on a lathe.  I have yet to scrap an armature.

Larry Elie 

-----Original Message-----
From: jim [mailto:fiskfarm mediaone net]
Sent: Tuesday, April 03, 2001 11:29 PM
To: snaugler earthlink net
Cc: elec-trak mailing list
Subject: Re: (ET) Mower motor bearings


Hi Steven,

Just to clear up what appears to be a misunderstanding, you use the heat
WITH a good puller. Heat alone won't do anything more than get it hot!
Sorry if I failed to make that clear. When one has been doing these
things for over 40 years I'm afraid one assumes too much and we all know
what that means.

Try to focus the heat just on the flange WHILE you are applying the
puller. I use the OTC brand in my work and they are solid. Grainger is
the place. I have the biggest as I work with large equipment but the
middle sizes should be fine. Mine is very heavy and can be awkward on
smaller items such as these.

Best, Jim