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MG TD TF 1500 - Generator bearing

I'm having trouble removing the bearing from the armature shaft of my generator. I can't get a puller behind it. Does anyone have a trick to get this off with out damaging the shaft?
Mark Butler

It isn't too hard to cut them off. Use a Dremel. Just don't cut too far. When you're almost through, use a hammer and chisel to break it off.
Steve S

See http://www.ttalk.info/Holcombe.htm and note Bob Jeffers' approach. Bud
Bud Krueger

I always thread a tap in to the bushing, then pull on the tap and it pops right out. I don't know off hand what size tap I use, I just open my tap drawer and pull out one that fits.
-David
D. Sander

I think that Mark is referring to the actual bearing and not the bronze bushing. I have cut them off in pieces with a dremel and after all is removed except the inner race I cut it as deep as I dare without damaging the armature shaft. Then I have used a Cape chisel th convince the remaining bit to come off.
ss sanders

Sorry, Mark. I was thinking bushing. Bud
Bud Krueger

There is a tool, I believe its called a bearing seperstot. it has a pair of knife edges that are pulled between the bearing and whatever is behind it with a pair of bolts. I broke mine. it was a cheep one from HF.
it does not remove the bearing it only moves it forward enough to use a normal puller. I can take a pix if needed.


Jim B.
JA Benjamin

Thought I had answered earlier, but obviously I didn't. The front bearing is very difficult to remove without a special puller. I would suggest taking it to a local auto electric shop and have them pull it. Cheers - Dave
David DuBois

Here is the kind of tool I mentioned.

http://www.mcmaster.com/#bearing-separators/=recj9p

on this tool, Mcmasters tends to be expensive, but perhaps it would not break like the cheep HF one I bought.

I did not mention that once you clamp it you can use a 2-jaw puller on the seperator to remove the bearing.

Dave has a good point, however. If you can find a generator repair shop they would pull the bearing for a very small fee.

I had broken the arm on my generator, right at the bolt hole. The hole that takes (supposidly) the only Whitworth bolt. I gave it to a friend to build up with weld. He had the bearing pulled at a generator shop he knew, just to be sure he did not ruin the bearing with the heat.

at no charge his generator friend checked out the unit upon repair. I know that it works.

Jim B.
JA Benjamin

You can often remove the outer race of a bearing from its housing by running a line of MIG weld around the bore. As this cools it pulls the race in and with luck it will drop out. This method is really useful for bearings in blind holes.


Jan T
J Targosz

A quick story of how I “discovered” what Jan T. refers:

Some years back I was faced with a bearing race in a gearbox end cap that was totally blind – absolutely NO way to get a puller under it. Cursing the engineers who designed it with no notches I devised a way to pull it by welding two grade 8 nuts to the race, directly opposite, to use to jack it out with a couple of bolts.

After welding the nuts in place I left it outside on the concrete to cool, face down. Later I recovered it to see how my solution worked and brought it in and chucked it in a vise. I thought I must be losing my mind as the race was missing! Sure enough it had fallen out on the concrete as it cooled.

Telling others about it was like the GEICO ad – everybody knows that! Well I didn’t and since then I’ve read it several times including Jan’s post.

It doesn't apply here of course but I agree that lacking the correct puller, cutting the race most of the way then splitting with a chisel works well in the situation
JE Carroll

I have a pilot bearing removal tool to pull the bearing out of a flywheel. I goes inside of the bearing and has two fingers that expand to get behind the inter race. It screws on the end of a slap hammer and works very well as it doesn't take much tapping to break it loose. HF has them for little cost. Snapon has them for 10 times the HF price, but unless you use it all the time, I wouldn't go that route. Just a suggestion.PJ
Paul S Jennings

The big problem with removing the front bearing of the generator is not so much getting it out of the front bearer plate (removing the three rivets allows the armature and bearing to be pressed out out of the plate). The problem that Mark is having is removing the bearing from the front shaft of the armature. There is very little space between the back of the inner race and the actual windings of the armature. Jim B's suggestion of suggestion of using a bearing separator will work in that the knife edges on the separator will slide in under the inner race and can them be placed in a press to push the armature shaft through the inner race of the bearing at least far enough that a standard bearing puller can be used to pull the bearing off completely. This method is probably going to damage the bearing itself, but a new bearing is not all that expensive and can be pressed back onto the shaft with very little effort. Cheers - Dave
David DuBois

Oh, my mistake, I thought it was stuck in the end plate. PJ
Paul S Jennings

Mark

The cost of a new bearing which you would replace as a matter of course while you had the generator stripped is negligible.

Therefore the destruction of the bearing is not an issue.

If you rap the bearing in a rag and then clamp it in a good vice by slowly tightening the vice you will fracture the outer bearing shell and displace the balls.

The next trick to removing the bearing inner is to carefully run a longitudinal weld for the length of the inner using an arc welder. Coat the armature shaft with grease and place a sheet of tin with an appropriate slot cut in it to protect the armature from weld splatter.

The weld will serve two purposes, one expand the bearing inner, two apply some heat to release the inner from the shaft.

This is an old Aussie bushy trick when you dont have access to pullers or a press. I have removed many electric motor and generator bearings using this process, it just takes a little due care and the use of correct PPE during the process.
G Evans

Thank you to all. Usually I would welcome any reason to fire up my welder but I decided to use the Demel approach. It worked very well.
Upon reassembly I notice that the thick ring that slides over the shaft before the fan sits barely proud of the end plate. Is it recommended to place another washer/spacer to bring the fan out further from the end plate ala the popular t-talk Holcombe instructions that are in the archives?
Mark Butler

This thread was discussed between 04/04/2014 and 06/04/2014

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