Ford 4000 Industrial - Alternator Problem

[whats this for]

Hi,

I'm new to TBN, and I'm a fairly new tractor owner. Actually, I currently have 2 tractors:
1964 Ford 4000 Industrial
1986 Ford 1910

I'm writing about the 4000. I bought it in July, when I knew even less than I do now. It was a mistake for a few reasons, leading me to buy the 1910 recently. I will be selling the 4000, but a few things need repair before I do that -- radiator, alternator, and oil leak. I'm writing hoping for help regarding the alternator.

The specific problem is that the pulley on the alternator broke.

I have an idea why it may have happened, but I could be wrong of course. The oil leak I mentioned above is somewhere on the front of the engine. The previous owner said it was minimal enough that he would just add a few ounces every 10 hours or so. I'm wondering if that leak led to oil splattering on the belt, which led to the belt slipping, which then led him to tighten the belt too far, and that was enough pressure to weaken, and eventually break, the pulley. (It broke a few months after I bought the tractor.) If that all makes sense, then I would want to fix that oil leak so I'm not passing the same problem on to the next guy.

Specifically regarding the alternator, it would be nice if I could use the same one, and just replace the pulley (and perhaps the fan that sits between the pulley and the alternator body). However, I am not having much success with that.

Originally, the 4000 had:
- generator & voltage regulator
- 6-volt system
- positive ground
The previous owner replaced the generator with an alternator. (The voltage regulator is still present, but not used.) It is still 6-volt with positive ground.

I figured that replacing the pulley would be easy. I brought the alternator and pulley to NAPA. Not so easy. He was not able to determine the brand/model of the alternator, although he did point out the following stamped into the back end of the shaft:
USA
INA
BCH 06604
The pulley itself doesn't seem to have any markings on it.

He spent probably 20 minutes searching online for information, but found nothing. And apparently he didn't simply have a number of pulleys in back that we could try to eyeball it. I got the impression from him that it is important to get the exact right pulley. I guess I thought it would be as simple as looking at V-belt-type pulleys that have the specific shaft hole diameter, and approximately the same outer diameter. But he said it is more complicated than that. Do you agree?

Another note on the pulley -- both it and the fan have a slot for a square key, but the alternator shaft does not. A friend pointed out a hint of yellow paint on the pulley, and suggested the idea that perhaps the pulley and fan are not the ones that came with the alternator, but instead are the ones from the original generator. Another note -- there is no set-screw to secure the pulley to the shaft. So the only thing that keeps the pulley from slipping on the shaft is the main nut. Is that normal? Or is that more likely the result of taking the pulley from the original generator and (inappropriately) using it on the new alternator? Should I be looking for a pulley that includes a set-screw? If I were to find the correct pulley, would it include a fan -- perhaps factory-attached to the pulley?

If I (with your input) am able to find a pulley (and fan?) that will work, then great. Otherwise, I would need to consider replacing the alternator, and would value any help you have in how to select the right one.

Thanks for your time!

 

[aczlan]

Do you have a picture of the alternator and shaft?

Aaron Z

 

[flyerdan]

It's normal to just have the nut holding the pulley and fan to the alternator shaft, most of them turn so that the nut is trying to tighten during operation. There is probably a hex hole in the front of the shaft to get on it with an allen wrench to hold it, but I've never had any problem taking a pulley off with a rattle gun, just hold the fan with a gloved hand or heavy rag.
You should be able to get a rough idea of the diameter and get a replacement; I probably have three or four out in the shop that would work. If you can't find the exact size it shouldn't matter as long as it's not so drastic as to require a different belt size.
I'd be curious to know how it broke; I can sort of imagine how one would fail if it was too tight, but I would have thought that the bearings would fail first.

 

[ovrszd]

Yeah, the belt being too tight didn't break the pulley.

Might try to find a replacement alternator first just to verify cost of that route. Then you'll know how hard you want to look for a pulley.

 

[aczlan]

Yeah, the belt being too tight didn't break the pulley.

Might try to find a replacement alternator first just to verify cost of that route. Then you'll know how hard you want to look for a pulley.

If it's a standard GM 3 wire alternator, a reman one is currently $50 on Amazon: https://www.amazon.com/dp/B000C9NN5S/
I have one on our David Brown project and have been very happy with it in the little time I've used it so far.

Aaron Z

 

[ovrszd]

If it's a standard GM 3 wire alternator, a reman one is currently $50 on Amazon: Amazon.com: ACDelco 334-2114 Professional Alternator, Remanufactured: Automotive
I have one on our David Brown project and have been very happy with it in the little time I've used it so far.

Aaron Z

He said it's still 6V Positive Ground. That might limit his choices??

 

[aczlan]

He said it's still 6V Positive Ground. That might limit his choices??

Good point, I misread his post as saying that it had been converted to 12v.
I would start with converting it to 12v (unless it's a show tractor).

Aaron Z

 

[ovrszd]

Good point, I misread his post as saying that it had been converted to 12v.
I would start with converting it to 12v (unless it's a show tractor).

Aaron Z

Me too, but to do it right that would require buying a starter. I think he's just wanting to sell it.

 

[aczlan]

Me too, but to do it right that would require buying a starter. I think he's just wanting to sell it.

Nah, starter will be fine. Would need to replace all light bulbs though.
Again, with a picture of the alternator and the shaft in question, it might be possible to find a pulley.

Aaron Z

 

[whats this for]

Do you have a picture of the alternator and shaft?

Aaron Z

Aaron Z,

I'm attempting to attach 4 pictures of the alternator.

You mentioned that you wanted to see the shaft - perhaps because I mentioned the characters stamped into the back -- so I included that. Other than that, the front end of the shaft is fully round -- no flat sides, no groove for the square key I mentioned that the pulley seems to allow for.

One picture shows that it is a one-wire configuration. Given that the electrical system is positive ground, that one wire would actually be for the negative, I guess.

And the other picture shows the break in the pulley.

Thanks.