I don't understand what all the fuss is about on this thread. I've been
rebuilding small electric motors all my life and have never had any instructions
whatever. Take them apart, replace the bearings, clean them out a little, make
sure all's a'tanto, put them back together the same way they were.
On really little motors I've sometimes had trouble
1) getting the centrifugal switch mechanism off correctly
2) getting the bells centered since they're built too lightly
To deal with the centrifugal switch, I try to gently remove the bell on the far
end from the shaft first, and see what I can see. Lots of times the armature
will slide out.
I have never had big trouble removing bearings from any motor up to 7.5hp and
I've never worked on anything bigger.
To deal with the bell centering issue (on reassembly) I mark the bells before
disassembly so I can replace them exactly as they were. Then I assemble the
motor lightly, and run it on the bench and tap the bells with a soft hammer
until they run as quietly as possible, then tighten them. I've gotten a couple
of small cheap motors to quiet down quite a bit this way.
Motor stators like being blown out with compressed air.
The only motors that I hate are the ones that when you run them they're noisy,
then when you cut the power for an instant, while they're still virtually at
full speed, they run silently, then when you restore the power, the noise
returns. Those I've never been able to fix, so I have always replaced them and
let the noisy ones go.