Pully came off generator shaft

qmdv

Well-known member
As title says the pully came off the generator shaft. Radiator destroyed. Evidently the nut backed off. When the fan hit the radiator the pully cracked on the generator side. Well I have a replacement pully and recored the radiator.

I think a locknut would be in order. Not sure weather to use a nylon inserted locknut or a locknut that pinches the threads.
 
If I wanted to use something to keep it from loosening I'd use 242 (blue) loctite. It will allow removal with tools but won't back off in use.
 
The exact same thing happened to me during a cross country tour to the Grand Nationals in1998. I found a radiator shop to patch up the radiator so I could continue the tour. Back home a month later, I called my insurance agent. My comprehensive insurance covered the temporary radiator repair, and the full cost of an NOS radiator plus shipping. The fan had come off and hit the radiator, so they wouldn’t replace “the cause” of the damage. I’ve told this story many times, and hopefully have saved the day for a lot of V8ers in the telling.
 
I rebuild a lot of these generators. That is a thin nut, I would NOT use an impact wrench, there is a good chance of stripping it. Loctite - yes.
 
Keep in mind that armature threads are a little different than regular threads. I have a set of special armature dies.
 
Keep in mind that armature threads are a little different than regular threads. I have a set of special armature dies.

The one I have is 1/2-20. I think I have an extra that is 3/8-24 diameter What diameter and thread pitch are you talking about
 
A 2 brush generator is suppose to have a jam nut (351124S) against the threaded pulley, and then a compressed clip ahead of the jam nut. The threaded jam nut is listed in the Ford Standard Parts Catalogue, and identifies the thread....which is definitely weird. 21/32" (.6562") X 20 TPI, X 17/64" Thick
I learned the hard way on running a fan with a 2 brush generator without the special jam nut!! Radiator cores ....AREN'T CHEAP!!
 

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A 2 brush generator is suppose to have a jam nut (351124S) against the threaded pulley, and then a compressed clip ahead of the jam nut. The threaded jam nut is listed in the Ford Standard Parts Catalogue, and identifies the thread....which is definitely weird. 21/32" (.6562") X 20 TPI, X 17/64" Thick
I learned the hard way on running a fan with a 2 brush generator without the special jam nut!! Radiator cores ....AREN'T CHEAP!!
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The thin nut and lock washer was used with a keyed pulley, as shown in the exploded diagram above, not the threaded pulley.

The thread on pulley used a locking clip on the end of the shaft, which had a small groove machined into it. As the engine normally spins, it tightens the threaded generator pulley on the shaft. The thought was that a retaining clip was all that was needed. Just in case the engine kicked back on starting, the clip would keep the pulley from uncrewing. As you can see. There is no space for a lock nut.

Over the years many pulleys got swapped around, including aftermarket pulleys. So there are a myriad of possible combinations. I rebuild a lot of these generators and have seen many odd combinations.
 

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The thin nut and lock washer was used with a keyed pulley, as shown in the exploded diagram above, not the threaded pulley.

The thread on pulley used a locking clip on the end of the shaft, which had a small groove machined into it. As the engine normally spins, it tightens the threaded generator pulley on the shaft. The thought was that a retaining clip was all that was needed. Just in case the engine kicked back on starting, the clip would keep the pulley from uncrewing. As you can see. There is no space for a lock nut.

Over the years many pulleys got swapped around, including aftermarket pulleys. So there are a myriad of possible combinations. I rebuild a lot of these generators and have seen many odd combinations.
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