Changing the Generator Bearing

E

Ed in Maine

Well-known member
I have taken the generator armature and front plate out of the generator housing. Now I am trying to remove the generator bearing. I am using a "clam shell" style puller which fits nicely behind the bearing with the threaded puller shaft placed at the end of the generator shaft. I can see the groove for a snap ring but no snap ring was installed. I'm finding that the bearing is very, very tight on the shaft. I have turned the screw on the puller and tapped the end of puller screw with a hammer and the bearing has not moved. The heavy washer is also on the generator shaft ahead of the bearing. Is there anything else like a snap ring (which is not installed) that could be keeping the bearing in place? Ed
 
Be sure to thread a bolt into the threaded hole on the armature
or you will for sure destroy the taper. I had one that I had a bolt to the bottom of the hole and bent the bolt and the taper. I ended up cutting the bearing off but the taper was already destroyed.
 
I was going to suggest cutting the bearing off with a Dremel. They make small diamond burrs for the Dremel which will cut through hardened steel. You would only need to cut through one side which would relieve the grip on the shaft.
 
The instructions I have mention removal of the outer plate and dust seal before removing the bearing. Only one retaining ring should be evident but it is a simple flat C ring and is the only retainer on the later cylinder shaped Autolite type generators. I've found them missing rings before. The front plate may be riveted but many have already been converted to screws with nuts. The rivets have to be removed if present. The bearing inner race is a tight fit on the shaft but may have been replaced using Loctite A puller is necessary but BobC has the straight skinny on using a new style bolt to protect the nose. They state in my book to avoid using the pulley bolt so I just use a modern SAE type grade 5 bolt. A grade 8 can be used but I've never had a major problem removing the bearing. It can be heated to a point just above 200 degrees where water can be squirted on it the get the bearing inner race to release. I'd only do this if I had to. Those old armatures are easily damaged so a lot of care has to be taken not to bugger it up.
 
There is a snap ring behind the bearing as well as in front of it. Is it possible that your puller plate has hooked under that rear snap ring???? If so, it will make it very hard to pull the bearing. Loosen and reset the plate.

Likewise, as others have said .............. make sure you screw that "sacrificial bolt" into the end of the shaft.
 
I restore a lot of model A generators. You have received a lot of good advice here. I can't add much. I have a bolt with the head center drilled in the lathe for the puller shaft point to fit in. It works just fine. The comment about the puller catching on the rear C-clip is on the money. I made spacers for my puller to prevent it from closing too much and catching the C-clip. See photo. I just make sure the puller is centered around the bearing. Lastly, on tight bearings I'll use a battery powered impact wrench on the puller. This pulls them right off every time.
 

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One other thing. That thick spacer that goes ahead of the bearing, be sure it is tight on the shaft. Many are loose and can spin freely which can damage the shaft and make a noise that sounds like a bad bearing. You may need to peen the inner diameter s little with a punch to make it a tight fit. The repro spacers a very loose. Originals get loose if they,'ve been removed a couple times before. Good luck.
Steve
 
Thank you everyone for your comments. I'm surprised that this bearing is so tight. Steve, your picture is exactly the puller I am using. Ed
 
Bearing could have been installed using some bearing retainer compound. Try applying some heat using a heat gun.
 
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