Delco 10DN and 1107872 starter rebuild

[hearnc843]

I have decided to go ahead and rebuild both 10DN alternator and 1107872 starter for my tractor (Delco Remy). Anyone have any suggestions for rebuild kits with quality parts, or any other suggestions as I undergo this?

I have not rebuilt a starter or alternator before, but I have been doing my homework- a lot of reading and video watching. The alternator went bad, and the starter has always smoked out of the top plug where the copper strap connects to the solenoid. Figure I might as well tackle both problems.

For now I have been charging the battery overnight when I know I will need to use it the next day, and avoided shutting in off as much as possible when using it.

 

[Jim.ME]

(quoted from post at 17:34:52 10/07/23) I have decided to go ahead and rebuild both 10DN alternator and 1107872 starter for my tractor (Delco Remy). Anyone have any suggestions for rebuild kits with quality parts, or any other suggestions as I undergo this?

I have not rebuilt a starter or alternator before, but I have been doing my homework- a lot of reading and video watching. The alternator went bad, and the starter has always smoked out of the top plug where the copper strap connects to the solenoid. Figure I might as well tackle both problems.

For now I have been charging the battery overnight when I know I will need to use it the next day, and avoided shutting in off as much as possible when using it.

With the Delco starter number, you should be able to search and find brushes, bushings and possibly brush springs. That would be about it for a ''kit''. Beyond that you should test the armature and fields. Do you have a multimeter/ Do you have a growler to test the armature with? Do you have a lathe to true the armature bars?

Similar with the alternator. The 7-digit Delco number should let you find brushes, springs and bearings. Beyond that it is testing before buying stator, rotor, diodes, etc. The 10DN is externally regulated. Have you diagnosed that the problem is the alternator, not external regulator? Does your alternator drive a tach? That might make a difference.

If you need to buy any of the major parts for either one, you may find getting a rebuilt will be more cost effective. I would consider up grading to a 10 or 12SI internally regulated alternator before spending much on a 10DN (unless needed for the tach), given you need to maintain the external regulator. Just my thoughts.

 

[hearnc843]

Thanks for the reply, just saw this now.

For the starter, I found various forms of kits on ebay. You can buy just the brushed all the way through everything you mentioned plus a new solenoid. I am going to take my time with that one I think, taking it apart and testing with a multimeter like you said. I a cheap $100 cheapo alternator, so I can still use my tractor in the meantime. Figure I can return it, or just keep it after as a backup. No lathe but I figure a drill and a high grit sanding pad.


I assumed it was the alternator that was bad, I had replaced the regulator about a year ago, and everything had worked fine until recently. The symptoms of the regulator failing was high voltage- I got about 19 volts at high rpm. I figured it must be the alternator because I don't get anything more than 12.5 at the highest after a full charge, even at high RPM.

I do need the tach drive for the alternator, so I did want to stay with the 10DN. I wound up finding a kit with everything needed on ebay. It had new diodes, bearings, capacitor, screws and everything. Hopefully that will fix it, if not I will probably need a new stator or rotor, or maybe just a new one all together. I am hesitant to update to the 10SI because I know I will need to modify some stuff, I prefer simple remove and replace fixes.

I already have the alternator apart, I plan on doing a rebuild guide, I have been taking a lot of pictures as I go. Will post with the updates when done

 

[Jim.ME]

I mentioned testing the starter with a multimeter [u:c2f6f110b2]and[/u:c2f6f110b2] a growler. If the armature commutator bars are not bad, polishing with a drill and sanding pad will clean it up but won't true it for best brush contact and life, as a lathe will. In a pinch I have chucked an armature in a drill press and spun it while polishing the bars with commutator paper. It cleans it some and takes some roughness out but doesn't true up out of round or deep wear. Use a non-conductive sanding product. Conductive grit embedded it the insulation between the bars can lead to shorting between the bars. Use a hacksaw blade to scrape the mica insulation down so it is just a bit below the commutator bars, after you do your sanding.

Did you test the alternator before you took it apart to see if the problem was the alternator or just figured it was the alternator because you replaced the regulator about a year ago? You needed to unplug the wire from the alternator's F terminal (you can leave the wire on the R terminal or not, the power wire needs to be left on the alternators Battery post stud. Then use a jumper wire to apply battery voltage to the F terminal. That will bypass the regulator and force the 10DN alternator to full output, if the alternator is good. If it had charged in that test, regulator failure would be most likely followed by a wiring issue. Once you get it re-assembled you can test your rebuild that way.

Some of this may be considered overkill, however it was the way I learned years ago, and works. It is good that you are giving it a try.

 

[hearnc843]

I don't have a growler to test the starter. It was still working, just figured it could use a rebuild, a bit of preventative maintenance. Thanks for the tips on how to clean it up, I do know someone with a drill press so I can try that.

I never tested the alternator in they way that you mentioned. I had tested voltage at the battery, and then again right off the back of the alternator just to see if there was a difference. Either way it was overdue for a rebuild or at least a cleaning. The stater was covered in dirt. You couldn't really even see the copper, I will post pictures when I have the project wrapped up. It was a farm tractor bought at auction, you could tell it had been through the ringer.

Thanks for the rebuild tips!

 

[hearnc843]

Ran into a problem on the alternator rebuild. There's a short internally, it popped a fuse immediately. I took it apart and found it, it the capacitor that is connecting the heat sink to the housing. I honestly though this was suspicious when I took it apart. There was what I thought was a metal washer under the capacitor screw, unless I was mistaken.

There are 3 additional insulators underneath the heat sink marked in green.

With the capacitor not screwed in, I get a high impedance reading between the heat sink and the housing, as expected. I believe that is because the diodes are doing there job, offering resistance and allowing 1 way flow of electricity.

The questions I have:
1. Is the red washer supposed to be plastic?
2. I noticed there is continuity between the 3 stater terminals, is that normal?
3. Anything else I should test with the meter while I have it apart again?


Please forgive my ignorance to all of this, I am a young guy trying to learn the way.

 

[Jim.ME]

It has been a long time since I rebuilt one and can't say for certain, but it immediately looks to me like the screw head (red arrow) in the before picture is slotted and the after is hex (center green circle). If so, you may have the wrong washer (it looks different) there as well. Do you have a Delco or some other manual you are using as a guide?

 

[hearnc843]

You were right, I mixed those two up. The screw at the capacitor on the heat sink needs to be insulated. I had been working off the parts diagram in the Massey parts book, but it is rough. It never occurred to me to look up a Delco manual. I was able to find an exploded assembly view that helped confirm that the capacitor screw needs to be insulated. I will include that in my rebuild guide.

Thank you for your help, and pointing out the swapped screws.

As a side note, I couldn't get my tractor started, seemed like a fuel issue. After 5 minutes of head scratching, I realized the fuel shut off cable on the injection pump had slid down a 1/4 or so, and the pump wasn't opening all the way. Coincidently happened as I change out the alternator

 

[hearnc843]

Here is a link documenting the rebuild:
10DN rebuild