Re: (ET) How do I change motor bearings?

["Steven Naugler" <snaugler earthlink net>]

Dave, I've done this to 6 motors, so hopefully I can give some pointers.

1.  The job is much easier with a split bearing puller and either a small
hydraulic press or an arbor press.
2.  You'll also need a 1-1/2 to 2 inch long 1/4-20 bolt with the head
curtoff.
3.  You must remove the blade holder first.  If the blade holder doesn't
pull off easily, screw the cut off bolt into the blade end of the motor
shaft.  Use a split bearing puller to support the motor by the blade holder
so that you can push the cut off 1/4-20 screw with the press.  When the
blade holder comes loose, the motor will drop, so hold on to it as you 
press
off the blade holder.
4.  With the blade holder off you can take the motor apart.  The bearings
should stay on the armature.
5.  Using the split bearing pullers and a press you can remove the 
bearings.
Keep track of any washers or spacers and note carefully their positions.
They must go back in the original positions.
6.  When you press new bearings on, only press on the inner races.  I
recommend replacing the original shielded bearings with sealed bearings.
7.  When you reassemble the motors, you must restrain the brushes.  There
are holes in the brush end of the motor that paper clips or toothpicks can
be inserted to keep the brushes out far enough to clear the bearing during
motor reassembly.
8.  If you have old motors where the blades don't have fiber clutch washers
but are pinned to the blade holders, you should purchase the new style 
blade
holder with fiber clutches.
    That was a very abbreviated set of rebuild instructions that only
touched on bearing replacement.  If you have other questions, just e mail
away.

Steve Naugler

----- Original Message -----
From: David Roden (Akron, Ohio) <roden ald net>
To: <elec-trak cosmos5 phy tufts edu>
Sent: Sunday, June 06, 1999 11:00 PM
Subject: (ET) How do I change motor bearings?


> Stupid question ... no, make that ~ignorant~ question (as the song says,
> ignorance can be cured, but stupidity is forever).
>
> My mower motor bearings are ~rough~.  After Matthew Magda's sad post
> about his broken motor magnet, I decided not to tempt fate any longer.
>
> Hmm, how do I change the bearings in my mower motors?  Getting to the
> rear (top) bearing seems easy -- take off the end cap, remove the nuts
> and brush carrier, and there it is.  (Does it just lift out?  I haven't
> tried yet.)
>
> But the front (bottom) bearing is not so obvious.  Do I have to pull the
> blade mount off the shaft?   What kind of puller do I need?  How do I
> replace the blade mount when I'm finished?  Once the blade mount is
> pulled, does the armature just pull out of the housing?
>
> I want to do this right, and not destroy an expensive motor in the
> process.  Please help, and thanks for the coaching!
>
>