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3G Alternator Disassembly Instructions??

70_Steve

Old Guy
Joined
Dec 13, 2002
Messages
8,317
I picked up a 130 amp 3G alternator reciently for a price I couldn't refuse. Relatively low miles, but it's a bit dirty plus I'd like to reclock it. I'd kinda like to disassemble it so I can clean up the case, plus I might install new bearings while I'm in there.

Does anyone have something close to step-by-step disassembly/reassembly instructions for the 3G??
 

RRRAAAYYY2

Bronco Guru
Joined
Nov 10, 2004
Messages
1,684
Loc.
Brantford, Ontario
Yeap 1-888-214-7774. Too long to write out and explain. Take 5 minutes on the phone and rather simple. Just have your alternator in hand when you call. Raymond
 

72Sport

Bronco Guru
Joined
Jul 8, 2002
Messages
2,954
I took one apart to reclock it and have the case polished. I also turned one to junk before I got it right. It has been a few years but here goes. No warantee.

Removed the pulley with an impact wrench. Removed the voltage regulator. Note the little round hole in the vr housing. When reinstalling use insert a paper clip in the hole to hold the brushes up. Remove the 3 screws holding the case together and the nut for the battery lead and the single wire connector. I believe the rear half of the case comes off fairly easily. The one I reclocked had the laminates jammed in the front housing. To remove them I supported the front half of the case on some blocks of wood pulley end up. I took a Craftsman small screwdriver (1/8" blade) and inserted it between the case and the wiindings. Don't scratch the windings. I placed the blade of the screwdriver parallel to the outside of the case. I tapped on the handle of the screwdriver with a small hammer. I moved around the circumference of the case until the windings dropped out of the front half of the case.

I think I tried to pry the laminates etc out of front case on the first one (the best one naturally) and ripped the wiring apart converting it to junk.

Hopefully I got it all right. It has been a few years. The famous electrical person on this board says don't do it.
 

RRRAAAYYY2

Bronco Guru
Joined
Nov 10, 2004
Messages
1,684
Loc.
Brantford, Ontario
A 1/8 punch will also work. Hard to get it out all the way doing that. Once about 3/4" of laminations are out you can hit the front housing while holding the rectifer bridge. There is a real science between what is going to break the rectifer bridge and what isnt. All I can say is you learn it by breaking 10 or 20 of them first, LOL.
The other option is to unsolder the rectifer bridge. There are 6 leads to it and you have to be really careful doing that too because if you get it too hot you will melt solder away from the diodes.
When reassembling make sure to clean the ring wear the stator laminations go until it is shiny first. Then apply a thin coat of anti0seize before puttingit back together.

Good luck. :) Some go real easy, others become scrap metal.
 
OP
OP
70_Steve

70_Steve

Old Guy
Joined
Dec 13, 2002
Messages
8,317
Thanks for the info guys. I may try this sometime in the coming week. RRRAAAYYY2, thanks for the phone number!
 
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OP
70_Steve

70_Steve

Old Guy
Joined
Dec 13, 2002
Messages
8,317
72Sport and RRRAAAYYY2. Thanks a bunch guys for the direction and the hints on getting this 3G apart. Went much easier than I thought it would. Removed the pully, and the VR/brush assy. I noticed the inboard brush was worn much more than the outboard one. Remove the rear case and noticed a little white corrosion on the aluminum. I lightly tapped around the outside of the case where the laminates fit. Then used an 1/8" punch, like RRRAAAYYY2 suggested, to get the laminates and coils moving out of the case. I was surprised that all it took was just a few light taps on the punch around the case, then a couple more light taps around the outside of the case, and the assy. just dropped right out in my hand.

I need to replace the brushes, and it looks like they are not replaceable, as the wires are epoxied in place. So I will probably go to a local alternator shop and pick up a new VR/brush assy and some new bearings.

The problem I now have is that the inside ring, where the brushes ride, is worn probably 1/64" or so. Not sure if that's able to be cleaned up or not. I've heard of the armature's being set up in a lathe, and those rings being turned down flat. So, I'm not sure what my alternatives are, besides packing the whole thing up and taking it all to the alternator shop. Anyone got any ideas???
 

72Sport

Bronco Guru
Joined
Jul 8, 2002
Messages
2,954
My local shop wanted $35 for a rebuilt armature. A used 3g is about $20. You might go shopping and get another 3g with good slip rings and good brushes. I think the VR is about $15 new.
 

RRRAAAYYY2

Bronco Guru
Joined
Nov 10, 2004
Messages
1,684
Loc.
Brantford, Ontario
I can probably get everything you need dropped shipped to you for cheap. Very common problem with the slip rings, and most of what you find in the wrecking yards will have varying degrees of this problem. Let me know if you have the bearings already. I can put together a package deal for you. Also can upgrade your rear bearing to a little bigger one if you have bearing retainer compound.
 
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