Opening the motor,

3 bolts through the housing and into the gear case. Cut the rubber away from the bolt heads to get the socket on. They were tight.

 

Pull the gearcase off the housing. The motor worked fine, but obviously has had water in the case.

I think most of the corrosion is superficial, and is not an issue yet. Any more and it would have been. We'll see what the other 3 look like.

 

Push the brush springs off the brush housings then remove them. Push the right side brush out. It's the ground brush and is soldered to the case. Put a small screwdriver in the plate clips and unhook them.

 

Gently work the plate up and over the armature shaft bushing. Be gentle on the wire where it attaches to the stator coil. Mine is ready to break off at the arrow. It can be repaired.

 

Some of the rust left in the case. I turned the case over and tapped it lightly. A lot of rust fell out from between the coil and case.

You cannot remove the coil. It's staked to, and is a part of the case. I think it's fine though. Just.

 

This is about it. The little bushing on the end of the shaft pulls off. The rotor itself is dirty, but in good shape tested with no shorts.

 

 

Oh yuck, the motor sure looks nasty inside. Amazing that it still worked good.

I'll be curious to see if it makes a difference in the function of it when you get it all cleaned up.

Kinda reminds me of repairing the electric motors running the hideaway headlights on the 63 vette.

So glad to see this thread Mark. I've never attempted this and Beaumontguru and I were talking about this very thing on one of our recent auto wrecking runs.

I don't see it in your pictures but is there any way to replace the male electrical terminals in the end of the motor, the ones inside the white cup where the connector snaps in?

I can arrange for one  that you can wreck. I have a set of regulators here for our friend and all 4 motors have one terminal rusted off. The seller was nice, he gave me the motors with the regulators and priced them as if the regulators had no motors on them when I showed him the terminals had rusted off. 

I'll pull one motor off and put it in the box of stuff that is going your way some day.

I'd take a lefty carl thank you! Couldn't be better timed.

One through bolt snapped off removing it from a left. So one bolt and a left gear housing will be put to good use.

I think the only real serviceable parts are the two brushes. A short in the stator winding or a corroded plug would probably render the motor body as scrap. A shorted rotor you could probably switch it with another, but from what I've seen in images, the worm drive gear on the shaft (and the driven nylon gear) can be of a differing ratio through the models and years. The breaker points could be removed with some effort. Could the entire board be the service part?

I've not seen any listing for service parts though. Maybe a Delco parts catalogue might show something? You'd have to harvest the best parts from any collection of motors you have. So keep them if you find em'.

The one thing to be very careful of when lifting the brush board over the shaft, is this connection point shown below. It's very delicate and will get work hardened and weak if manipulated too much. My first motor I took apart got really loose and weak there. I cut the entire wire away and re-soldered another one it it's place. One should try to straighten the curve in the wire when pulling the board up over the shaft. Try not to manipulate this point too much.

Rust in the casing looks bad, but doesn't seem to affect it's function, although too much will obviously kill it at some point. This motor had a dead moth inside go figure.

Pre closeup,

Gently open the breaker points, fit and do a few pull throughs with a folded over piece of fine sandpaper, then a drop of brake clean on the points while holding them open,

 

Clean up the motor case to gearbox mounting face a bit, add some grease to the worm gear.

Not too much, you don't want a blob pushed down tthe shaft when you slide the gearcase on. Too much grease, and that bronze bushing will wipe the grease down off the shaft.  

I feel a blob could find its way down and around onto the commutator, eventually inhibiting the brush contact. So this step is important.

 

Clean the threads on the case bolts best you can.  Add a dab of never sieze, and run them into the gearbox threads by hand. Ensure they go in with little effort,

 

When they are 100% clean, grease the driven gear teeth. Then the cup seal, the gear case, in the center bearing hole only.

The image shown is actually WAY too much grease. May be my imagination, but when testing the motor it seemed a little draggy. I wiped most of the excess off the plastic gear face and the gear case recess and it seemed to actually pick up speed.

The nylon gear face does not run on the gearcase. The gear shaft bottoms in the case hole before the nylon makes contact. The only spot it might make contact is on the small flat seen below the worm gear opening. In theory, depending on the direction, under load, the gear gets pulled down onto the flat, the opposite direction it gets driven upward but is captured by the regulator bushing. I know in one direction the gear wants to moves up, when first testing these motors, two spat the gear right out onto the bench.

 

Thank you for being brave enough to tackle these.  Beaumontguru and myself were discussing this not that long ago and neither one of us really wanted to take a shot at it! 

Question for you. Can you notice a difference it how it works on the bench now vs before you had it apart? Visibly faster, quieter etc?