I know lag bolts is a really bad idea, but he's replacing the bearings and probably doesn't care about the old ones. And I don't see that it can be done by holding the inner race without a very special tool.

If he's going to bang on the shaft, probably a brass hammer or at least hitting a bar of aluminium to protect the shaft from a steel hammer would be the right answer, but hitting the shaft is just so wrong.

Ira

Actually, in hindsight I'd say that if lag bolts let him pull the bearing gently without damaging the shaft, it was a really good but very unconventional solution. Bearing are inexpensive, the shaft, windings and possibly the fan are precious and anything you can do to get the bearing off without damaging anything else is a perfectly reasonable solution. Now, I would never try the lag bolt solution if it wasn't a very last resort, I would just make the puller but not everyone has a lathe in the garage.

Ira

Ira I have 35+ experience as a machinist.. If the lag bolts method works, I am sure the holding the fan by hand and tapping a bolt screwed into the end of the shaft or TAPPING LIKE A DOCTOR a Rod with a Hammer (NOT THE SHAFT END) will work also.. Your method sounds like a big PITA with a lot of cussing IMHO..

If you think the Lag Screws is a good idea go for it...

I was an industrial maintenance mechanic for many years and would take an air grinder or Dremel carefully to the outer race of the bearing and split it off. Then clean the remains off the inner race with solvent. At that point cut the inner race with the Dremel. When you get close to the shaft, split the race with a cold chisel. If you nick the shaft with the Dremel don't worry as it is too close to the center of the rotational mass to upset the balance, just try not to nick the shaft with the chisel as this will raise a ridge that will have to be filed off. Go slowly and it will be fine.

Use a nut splitter:
http://www.fastorq.com/wp-content/uploa ... _Step1.jpg

I am facing the very same problem, but with a Major. But before getting here I should be able to get the whole thing out of the motor. How did you do that. I mean if I would try to pull out this inner part of the motor, the ventilator would get stuck in the external part (sorry for missing the right terms). Or did you get out the whole motor and pulled out this inner part upwards. If yes, how? its incredibly stuck in the aluminum body of the grinder.
Thanks.

Cut it as shown in the video above. It matters not if you nick or gouge the shaft with the cut off wheel. Trying to force or bang it off is a much higher risk of damaging the shaft. A dremel with a reinforced cutting disc(s) will do the job since most folks don't have a drawer full of air tools in their garage. I've cut more bearings and retaining collars off of semi-floating axle shafts than I'd care to remember.