M1028 Alternator Rebuild Questions

[Corvette1974]

Hello.

I am rebuilding my alternators in my 1986 M1028. They are the original military alternators, and just due to age they need to be rebuilt (the truck has 34,000 miles on it).

I have them apart, and have a few questions

1: To remove the rear bearing, should I knock it out or press it out? And which was does it go out (or does it not matter).

2: To remove the front bearing, I need to remove the pully. What is the best way to do this? I tried holding it and using a socket, but I think a impact gun is needed, but still how do you hold it?

When reassembling...

1: Which way does the rear bearing go in, and which way does it go in? Also, whats the best way to set the right depth of it, so the rear of the rotor doesnt hit it?

2: For the front, should I just retorque the pully with a breaker bar or impact it on?


Also, the stator and rotor have some surface rust on them, can I paint them? And when cleaning the parts, I know you need special electrical cleaner...Can I use "QD electronic cleaner" (the napa stuff I think)?

And when looking for problems with the stator/rotor, other than obvious burns, is there anything specific to look for?

Thanks,
Will

 

[Corvette1974]

And could I use my ultrasonic cleaner on the rotor/stator?

Will

 

[Corvette1974]

I'm going to try impacting off the pulley and pressing out the bearing.

Hope it goes well.

Will

 

[Warthog]

You'll need the impact to remove the nut for the pully. The pully and fan will slide off.

When you remove the rear bearing, make sure you use some sort of backup/support. If not the case can CRACK.

It will slide either direction, but I always work from the outside of the case.

The front bearing is held in with three screws and a cover. It should slide out.

Reinstalling the rear bearing, use your support and tap it in until it is flush with the rear of the housing.

Use the impact to reinstall the pully nut.

The TM has a step by step procedure to test the stator and rotor. The other test for the regulator and rectifier really don't apply as you should be relpacing them.

I have seen new internal parts that are bad from the factory.

Of course YMMV

 

[Warthog]

PLEASE make sure you replace all the fiber and plastic washers in the correct location.

This is what keeps the internal electrical components separate from the metal case and makes the unit an "isolated ground" alternator.

 

[Corvette1974]

Thanks for all of the great info! I am doing the bearings later today.

All parts are being replaced. I will absolutely replace all of the isolating washers in the correct locations.

Do you know which TM has the test info?

 

[Warthog]

Do you know which TM has the test info?

TM 9-2320-289-34. Section 4-2, page 4-2

 

[Corvette1974]

TM 9-2320-289-34. Section 4-2, page 4-2

Awesome. Ill look into that when I get home.

Thanks,
Will

 

[Corvette1974]

Good stuff. Bearings punched out and pulley taken out. Further testing and dissassembly will occur when I get home from my class.

Will

 

[Corvette1974]

I checked out the TM, I love those things.... I'll do the testing tomorrow, and hopefully if the kit arrives I'll assemble it.

When installing the new bearings, do I or should I need to add grease to them or are they pre greased? If so, will my valvoline synthetic grease work with them?

Will

 

[Warthog]

The new front bearing should be enclosed and prelubed. The old one may not be enclosed.

The rear should have some lube. If not add a little but do not over grease.

 

[Corvette1974]

Alright, I'll add lube as needed.

One thing, I got the rotor out and the bearing retainer and bearing out. The bearing is a sealed bearing, correct?

It seems the backing plate of the bearing has stuck to the bearing retainer. Should I remove this (it is part of the bearing and will be replaced with the bearing, correct?) and if so, how should I go about it....its stuck on pretty well.


Will

 

[Warthog]

Looks like the old bearing wasn't sealed. I have had a couple like that.

The new bearing is more than likely sealed with a redish plastic cover. See the earlier picture.

Just leave the red cover in place, install the bearing and the metal retainer. You might need to add a little grease to the felt wiper on the bearing retainer.

P.S. I have all these pictures saved to my work computer from when a rebuilt a unit a couple of years ago.

 

[Corvette1974]

Looks like the old bearing wasn't sealed. I have had a couple like that.

The new bearing is more than likely sealed with a redish plastic cover. See the earlier picture.

Just leave the red cover in place, install the bearing and the metal retainer. You might need to add a little grease to the felt wiper on the bearing retainer.

P.S. I have all these pictures saved to my work computer from when a rebuilt a unit a couple of years ago.

Oh so that plate in the retainer is a part to the retainer and it should be left (the part with the felt that is attached to the retainer)? Does it matter which way the new bearing goes in and I should add some grease to the built in retainer felt thing?

Will

 

[Warthog]

YES on leaving the retainer part alone, NO on which way the front bearing is inserted and YES on a dab of grease on the felt thing.

Does your new bearing have the plastic cover over the roller bearings?

 

[Corvette1974]

YES on leaving the retainer part alone, NO on which way the front bearing is inserted and YES on a dab of grease on the felt thing.

Does your new bearing have the plastic cover over the roller bearings?

Haha thanks I just wanted to be sure. I haven't gotten the kit yet. Hopefully its there when I get home.

Will

 

[parlay100]

I rebuild alternators for a living. Ask away...

 

[Corvette1974]

I rebuild alternators for a living. Ask away...

Nice. Well for now I'm good but once I start the rebuild and test the rotor/stator ill let you know.

Thanks,
Will

 

[parlay100]

You picked a good one to start with the 27SI series is nice and simple. If you need some parts let me know i have barrels of them.

 

[Corvette1974]

I got the rebuild kits and it has a sealed bearing for the front and a normal bearing for the back. The rear bearing has some green grease in it. Should I shoot a shot or two from my pneumatic grease gun into it? I use Valvoline synthetic grease with moly.

Will