The Stovebolt Site Forums The Shop Area The Electrical Bay 57 3100 Starter Rebuild Advice

My starter has been having a few performance issues since fall (at it's age, I guess it's earned it...me, on the other hand...). Every now and then, at first, it would just growl and rumble when I hit the foot pedal. It was obviously spinning itself, but not the engine. Sounded mean, but did nothing. I would wait for a second, and try again and it would catch.

It's been getting progressively more common, so I decided to order a rebuild kit and have a go at freshening it up. Read a lot in the forums, but did not see much in the way of tutorials and what-ifs, so here I am...

Here's the starter in situ. When I took off the bypass and switch, I noticed that I was getting a short in the thin copper springy-thing that engages with the switch plate inside. Is this anything to worry about?

Opening the case, a ton of oily dirt fell out. To be expected, I guess, but a surprise to me. No wonder these have to be bulletproof.

First question: What solvent or material can I soak this in without damaging the field coils or windings?

Next, the commutator end...Here's what mine looks like. The copper looks like it is pretty darn worn down. Is this normal? Or should there be more "meat" in the copper part between the channels?

So, before I get too far down the road, is this thing worth repairing and cleaning up?

Do I need to find a way to grind the new brushes in my kit to match the commutator curve? If so, how?

I will document any repair and cleanup as I go, but I'd love some advice on whether I am working with a good unit to start with. No sense putting a new kit into a gone starter.

Thanks,

Jim

Looks like you have a good rebuildable unit. The main trouble you are having is the starter drive. I believe one comes with the kit. The rest looks good. The brushes look good enough they don't really need to be replaced. If you do they do not have to be curved or broken in. The thin copper sends current to bypass the coil resister. If you put it back like it was it will be OK. I wash the housing & field coils with a spray washer. Soap & water will work. Check the bushings. They are probably OK. Put a pinch of grease on the bushings & the shaft that the drive slides on.

Thanks Wrenchbender,

I found a couple of references to using alcohol to clean these up. Tried that and then ended up using dawn and hot water. Worked very well. Appreciate the advice.

Here's a better photo of the commutator. Hoping this is good to go. Is this something to worry about? Seems that in a previous rebuild, someone banged the wires into eachother. Do I need to worry about shorts between them? And, is there a way to check for issues without a growler?

The kit came with a new starter drive, which I will install. Following the shop manual instructions right now. Not all make sense. Any tips on the snap ring and thrust washer?

May have a bigger issue than that...just compared the old to the new starter drive. Here's the side-by-side. The new one is half an inch shorter than the old. Did I get the wrong kit? NAPA is usually pretty good about giving me the right parts. The rest of the kit seems like it matches what I have.

What do you think?

And here's my reassembled switch. Is this the correct location for the springy-thing?

Also, since the kit has the bushings, how do you get the old commutator end plate bushing out?

Thanks again,

Jim

That is not the right drive. It is for a newer model. To remove the drive, tap the retainer back off the snap ring. There is a tool for removing the snap ring but a pair of channel locks & foul language will get it off. Then you can remove the retainer & drive. Sometimes there is a ridge where the snap ring was that you will have to file down. Check the rear plate on the armature. If there is no looseness you will not need to replace it. I drill a hole in the back of the bushing & drive it out with something sharp. Some guys run a tap down in it till it forces it out. You can go over the commutater with some fine emery cloth. It will be OK.

George, is it a flat nosed snap ring plier? I've always used the channel lock and cuss method.

Jim, when I had to put a starter drive in my truck, I went to all the flaps in my area and they all kept trying to sell me the wrong one. I ended up going to an automotive starter alt repair place. Tony knew what I needed, and got it for me the next day. Also sold it to me for a lot better price than what my flaps wanted.

Thanks guys,

I'll give the mail order system one more try, then it's off to the starter shop.

After several hours of research, I think I ended up with an AC DELCO model 2100 starter drive. The OEM number SEEMED to comport with parts numbers on the GM wiki, but I must admit that I had a heck of a time navigating those pages.

The 2100 should be here Wednesday, at which time I will check back.

Only reasons I did not go with the starter shop that's about 40 minutes away were because they ball-parked me the price of a new one for a rebuild (can understand that, over the phone), and I wanted to try this myself. We'll see if that was a good idea. So far, feel pretty good about it.

Back to you all soon,

Jim

The simple way to remove the drive-end bushing is to find a threading tap that will bite into the bushing a little, and just crank it in there. When the tap bottoms out it will push the bushing out of the housing. Clean up the chips and use a vise and a socket the right diameter to press the new one in. Check for fit on the end of the armature, and do a little scraping with a sharp pocket knife if there are any burrs or tight spots. Lube the bushing sparingly with some high-temperature wheel bearing grease as you assemble things.

The armature looks good- - - -no deep scores or grooves. Use a strip of medium-grit sandpaper (120 or so) and give it a good shoeshine to clean up any oxidation. Good luck!
Jerry

Thanks Jerry,

Will do as you suggest. If there is little or no oxidation, is the sandpaper thing needed? Just thinking that the scratches imparted might give the brushes LESS of a surface to ride on. Or am I looking at this wrong?

Here's the new starter drive (ACDELCO 2100) that I got from Amazon for about $30. It's on the bottom, the NAPA part on the top. Length is right, as is the tooth count and (seemingly) the pitch. I will make sure and measure diameters tomorrow, but right now, we are prepping for Snowmaggedon II, so will see. At least I may get a free day off tomorrow to work on my starter. I think that's a wonderful thing.

Here's a shot of the forward end of my old starter drive. Obviously rebuilt, but I wonder if that means the starter drive was a rebuilt unit or the whole starter.

Back soon,

Jim

always good to polish up the commutator Jim, altho I use very fine emery - and make sure you slide a point down the slots afterwards to clean out any dust buildup

Bill

Thanks Bill,

Do you think the switch and it's side spring look okay? Do I have it reassembled the correct way? Not really sure how to keep it oriented that way...when you take off the nut, the rivet end inside lets that thin spring ribbon move around a lot.

How about those windings I asked about in the 3rd post? Any worries about them shorting out?

As for the cleaning of the slots, I don't know if it's problem or not, but my 'slots' seem to be solid. I will try again, but I was worried I was working against phenolic or something when I tried to clean them out earlier. Pick just skipped out of the channel because everything was flush.

Let me know if you need more pictures.

Jim

there should be double nuts on that post so the first nut [w/lock washer] holds the post, another holds the wire .... if the winding wires aren't badly gouged or actually pressed together they shouldn't be a problem, but not much to be done in any case .... for the slots, just make sure there's some depression there and no ragged edges to damage the brushes - commutator looks like it may have been previously turned down

Bill

Alright...got it.

Another question, the manual shows an 'Assist spring' between the clutch assembly and the windings. As you can see from my previous pictures, mine did not have one on it.

Was this something left out by a prior rebuilder? Is it a critical piece?

The rebuild kit had a thin plastic washer that the instructions show going on before the clutch assembly, but on mine, it would not fit over the helical section so I could not put it there.

Is this another 'multi-use kit' kind of problem, or do I need to try to source another starter for parts?

Thanks for your time,

Jim

Starter commutators usually don't have the mica undercut. It's necessary on generators because the mica will cause the carbon brushes to wear quickly. The sintered-copper brushes starters use are harder than the mica separators used between commutator bars, so there's no need for undercutting. Just do a shoeshine polish with some type of sandpaper or emery cloth that has non-conductive abrasive. The warning against using emery cloth on a commutator is because conductive material can embed itself in the grooves on a generator commutator and short out the windings. Not much danger of that on a starter, but I've got a roll of non-conductive roll abrasive for electrical work just to be safe.

I've assembled dozens of starter drives without an assist spring or a plastic washer, so don't get too concerned about not using them- - - -they work just fine without those pieces.
Jerry

Thanks Jerry,

Appreciate the peace of mind...Will finish my reassembly when the bit of touch-up paint on the case dries.

I'll post results here once I get it reinstalled.

And, just to be double-sure...is this the correct orientation of things inside the switch?


Jim

Well guys,

Starter's back together again. I decided not to replace the brushes since there was more than half of the wear area left. Will save those for next time.

I went with the orientation of the inside of the switch that made sense (as shown in previous post) and reinstalled the starter.

Hit the pedal and.....nothing....

Forgot to reinstall the pedal linkage. Ooops...fixed that and...

She starts up on the first press and several thereafter. No more growling, no more complaining.

Thanks for all the advice and assistance.

Jim