Starter / Generator throwing black dust
 

I'm pretty sure this is an issue with the belt?

Black, soot all over the front...

Is there a sharp edge on either of the pulleys, or did they have rust pits on them? I have had both of those issues turn a belt into dust before.

Well, replacement S/G on the way.. I discovered the issue.. well, from the outside.. I'll tear into the S/G soon... the pulley would sit static while the shaft would spin like crazy.. I'm not sure exactly where the dust is coming from but the S/G was making one heck of a racket when I ran her for 5 min tonight... we'll see what she looks like on the inside... the S/G had enough umph to turn it over once or twice if you pulled (the belt by hand) one compression stroke and got it positioned to turn on the down-stroke.. but the next time it got to the upstroke there wasn't enough torque in the starter to turn over and the shaft would just spin...

good times...

My 71 was doing that too. It has allready been rebuilt.....must have been the belt because it dont make the black dust no more.

So, how in the heck do you get the nut that holds the pulley off? Any tricks? My pulley stays put as the shaft spins, looks like it needs a couple of washers to tighten against the pulley. Quite a gap.

Take it apart and put a rubber strap wrench on the armature? just a guess. Take it to a reputable starter shop.

Gotta use an impact.

Tried the strap wrench.

Dag nab it! That's what I suspected.

I managed to break the nut free.. by wrapping the internals in rubber, and using a pipe wrench on the armature (wrapped in rubber) I was able to finally remove the nut. To find, as I suspected, that the pulley key was absent.. from what I can see it appears the previous user (of the S/G, not tractor) may have stacked some washers and tightened it down against the pulley to make it work! The inside washer was worn down significantly from rubbing against the pulley shaft... until there was enough room for the pulley and both washers to just spin freely.. IE not move when the armature shaft moved... good grief... and this was sold as NOS! NOT!

I suppose it could have been NOS , but someone in the parts department stole the key for a good customer.....or his own cub. That's the problem with NOS... It is OLD stock.. and there can be a reason it is still hanging around. Either it has a wee little problem like you found, or it has deteriorated some from sitting around and nobody wanted to buy it for list price, or sometimes it is just old stuff that is obsolete.

FWIW:
A lot of Generators and alt.s were/are built without keyways in the pulley/shaft.
They found out back in the 60's that they could be eliminated saving a penny or two in manafacturing costs.
If the nut is @ the proper torque, no key is needed.

If you think of it, not only the price of the key, but the cost of machining the keyway and the tooling costs. :bigthink:

Given the amount of rust on the armature and the field coil insulators, I'm guessing if it was NOS that it was stored in outside... from the looks of the entire setup it was used and sold as NOS... the nut was at the limit of the threads, a well worn and tweaked washer was followed by another lock washer. OEM calls for a single lock washer (as best I can tell)

The collar spacer between the back of the pulley and the front plate (frame drive end).. is missing, but appears to be part of the pulley.

Further wierdness is a bearing just like the bearing in the drive end that is mounted just past what appear to be splines on the end of commutator end... I can't find this bearing anywhere in any parts diagrams...

That makes sense, but there are too many other anomalies for me to accept that the key was just left out for cost savings... funky washers, weird bearings, rust on the INSIDE of the S/G...

If you are talking about a ball bearing on the back end of the Generator, and a splined shaft sticking out 3/4" or so,
Delco made that type of generator for applications like a power steering pump, it bolted on the back of the Gen with 2 bolts, on early oliver tractors (6V.) and G.M cars (12V) in or about 1958 and earlier.----
I think I still have one in my pile of goodies.

That sounds like it.. so perhaps someone put the armature off of one of those into my S/G shell?

Would that even work?? Sounds like a good way to add hydraulics to a tractor that doesn't have it.

I have no idea, it works in my case.. I'm going to clean up this unit, put a woodruff key in it and mow my jungle.. still waiting on the "supplier" to return a "rebuild" unit to me in exchange for this one... I'll upload photos...

Back in the day, the weak point in a generator was:
#1 the brushes would wear out and
#2 the rear bushing would wear out, usually wearing the armature shaft also.
The rear bearing Generator was desirable, and it was considered heavy duty as it had a #203 ball bearing and no worry that the oillight bushing/armature shaft would wear out.
although early generators had an oil cup to lub the bushing, folks just didn't bother to do it so in later years they eliminated them.

The bearing generators are available today (though pricy) as many of us classic car restorers need them for originality.
On the hyd pump application, they are rare and very pricy.
there just weren’t many vehicles back then that had a power steering option.
it is easier to go to the separate pump system that came out in about 1959/60
I'm attaching a picture of Generator/pump combo.
There were 4 variations of the combination, but were basically the same for this discussion purpose

Here are some shots of my S/G

Uhhhmmm, in picture #4, is that bearing seal just a lump of melted plastic???!!!

If that's grease, it's waaaay too much for a motor.

If it's plastic, I think we know where your problem is.

New bearings from Fastenal could make your world a better place. I just figured out my bearings are out, so I'll be ordering a set myself. When I bought bearings for my air compressor motor, I was amazed at the price! Try them. I'm not associated with them, they've just impressed me with the stuff they carry.

The commutator looks good, brushes also.
I'd turn the bearings to check for roughness/play and if good, no need to replace them. I would rather have a little extra grease from the bearing than none, but there seems to be an excessive amount there.
That is just a plain unit with optional bearing in the rear, it is not the one for a power steering pump which I have attached a picture.
The shaft shows a little scarring from the pulley slipping, so I am with you on putting in a woodruff key and you’re good to go.
The little rust inside hurts nothing.

I now understand why there was no woodruff key.. the spacer behind the pulley was too short by at least 1/4 inch... I'm now wondering if the pulley is the wrong one and that may be leading to the copious amounts of black "dust" on the front of the S/G.

My replacement "rebuilt" unit will be here on Friday, so we'll have a comparison look see at that unit and the PO of my cub says a local Alternator shop has one of his old S/G's that I plan on picking up for parts...

This has been quite an adventure so far.. I was thrilled to at least get the tractor running last night to mow...