Generator end play

rusted

Member
I just took the generator off my car and there is a lot of end play. It is a type 2 tube type. The pulley goes back and almost touches the nuts on the front plate. I can push and pull the pulley in and out 1/8 inch or a little more. Is there something wrong or is this normal? Thank for any help.
 
The lock washers go under the screw heads so the nuts set closer to the end plate. If someone put the lock washers under the nuts, then the pulley can sometimes rub. 1/8" is a bit excessive. You should feel practically no end play.

The front bearing, spacers, felt seal, seal retainer, wavy washer, lock rings, and bearing retainer plate control the end play. I've seen people leave out the front spacer, or wavy washer, etc. and that will cause excess end play. You need all the front plate parts shown in the picture, even if you install a new sealed bearing.
 

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thanks for the reply, Tom. This was a new (rebuilt) generator from one of our favorite vendors. I got it last august. It may have only 1000-1200 miles on it. I will take it apart and make sure all is in order in there. Thanks again
 
By "favorite vendor" do you mean the generator man in Texas? I'm fixing one of his right now that had a messed up bearing, excess end play, and the armature was grounded (shot).

I see some armatures where the bearing ran dry, then spun on the shaft, so I have to put a heavy knurl on the shaft to make the new bearing fit tight.

I drill the back side of the rivets to remove the rolled edge, then use a small straight punch to poke them out the front. You have to be careful with the drill because it's at an angle and can slip and hit the armature windings. Then buy the rivet nuts from the Model A parts houses to secure the bearing retainer plate.
 
Tom is right (of course).
The front bearing is a slight interference fit. It should be snug in the housing. If not Knurl it or if you don't have a knurling tool the unapproved but effective method is to take a center punch and lightly tap the housing with the punch where the bearing rides. it will give you a snug fit. If it is sliding on the armature shaft and not the housing you need to knurl where the bearing rides or put a drop of lock-tite on the shaft.
The point is there is friction and you don't want the inner and outer race of the bearing spinning in the housing or on the shaft. The hardened races over time will win out over the softer metal.
Typically rewound armature will have knurled shafts as they are in very short supply if available at all. Like using the center punch it raise the metal to give a good fit. With a slight interference fit it doesn't take much to have no fit at all. Once it starts slipping the shaft or housing becomes short lived. Now please don't be hard on me folks but you can center punch the shaft lightly to give the lock-tite something to anchor to.

Sorry Tom I see you addressed Knurling. Didn't mean to step in on that.
 
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OK, I took the generator apart and this is what I found. The lock washers were under the nuts. the front bearing spun on the shaft. I center punched it and now have a good fit. I think I will put a drop of loctite on to make sure it doesn't spin again. Now. how much space should there be between the front cover and the outer snap ring? Does the bearing fit up against the inner snap ring? And what kind of Loctite should I use? Thanks for the help. I think we can beat this problem.
 
There should be no spare space between the lock rings and bearing/spacer. Look at my picture and make sure you have all 8 pieces that fit on the front of the armature. My picture shows 7 pieces loose and the rear lock ring on the shaft. These lock rings are soft steel, so you can easily spread them with a couple thin screwdrivers. When you reinstall the lock rings make sure you use a pliers to squeeze it completely round and inside the groove. If it's just a little loose it can rub on the thin retainer plate, or on the front end plate.

Give your shaft several center punch marks evenly spaced all around where the bearing fits. Use a new sealed bearing if you feel any play or roughness. Probably any Loctite you have will work in conjunction with the punch marks.
 
I would use the "blue" Loctite on that bearing. This to be sure of removal without heat should the need be.

Joe K
 
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