Generator Nut Comes Loose

[Stephen Wong]

Has anyone experienced their Generator Nut coming loose and eventually off while driving?
I have a 64SC with a 12v generator and had a new fan belt and generator nut installed recently. After only 4-5 short drives the generator nut came loose and off while I was on a drive yesterday. I was able to reinstall the shims and nut and tighten the nut to get home. When I got home I checked and the nut was still tight.
There are 7 shims between the pulleys and 2 under the nut. The fan belt tension feels right.
Any suggestions or ideas as to why this is happening?
thanks,
Stephen Wong

[Ron LaDow]

Stephen,
I'll ask others with better memory comment on the number required, but mine says 11.
Regardless, have you checked fore-aft alignment between the two pulley? There is some adjustment available at the generator end.

[Bruce Smith]

Ten

[Ron LaDow]

Ten

Danke,

[John Brooks]

Look between the pulley and the third piece and get the missing spacer out before you lose it.

[David Jones]

The generator fan pulley nut is very similar to the fan nut but a different configuration. It is also thinner than the generator pulley nut. Make sure you have the correct nut as the fan nut will not tighten down properly on the pulley. There should be a total of 10 shims. at least a 1/2" deflection of the fan belt midway between the two pulleys on the right side. I can give you the correct dimensions tomorrow but someone on the West coast will be able to measure one tonight I am sure. I am just not going to get dressed and walk the 100 yards to a cold garage to check late at night.

[David Jones]

Ten shims minimum and check to see if it is the correct nut as the fan nut is similar but will not tighten down on the pulley wheel. Not enough shims means that the belt will be too tight because the pulley has been tightened down on the belt not on the shim pack.

[Martin Benade]

And probably you meant 1/2" deflection, 12" is a bit much when you push on the belt!

[WilliamVaughan]

Get this tool.
https://fanchers.com/shop?olsPage=produ ... her-handle

It is very much better than sticking a screw driver in the notch.

[David Jones]

Correct Martin. I tried to correct it after I sent it but my internet connection has been spotty being on WIFI, so was unable to do it but it is now corrected. I should add that I have never had a belt come loose but I have lost numerous belts over the last 50 years and all were due to either age/wear and occasionally the wear was accelerated by some kind of misalignment. The fan belt will last decades if aligned correctly and will normally never come loose if installed correctly though some extra slack ensues after initial installation so expect to have to remove one shim inside the first 500 miles of new belt install.

[Jeffrey Leeds]

Get this tool.
https://fanchers.com/shop?olsPage=produ ... her-handle

It is very much better than sticking a screw driver in the notch.

Thanks for posting this link. I have one already that I have been using for more than ten years. I've always wanted to get another for my shop tool chest - it's a pain to keep digging the one I have out of my travel kit buried in the smugglers box.

[Doug McDonnell]

Stephen As David stated pulley nuts and fan side nuts look similar but are different. Easy way to tell is look at the inside of the nut. Pulley side has recessed inside nipple. It is also thicker. See photo showing differences here: viewtopic.php?f=1&t=39685&hilit=generator+nut

[Al Zim]

You can put the generator pulley not on the fan side but I do not recommenced it. The end of the generator pulley nut should be flush with the end of the armature. This insures that the generator nut will not touch the end of the spacer that holds the shims. Zim's has a special screw driver with a rectangular shank that holds the pulley firmly without distorting the opening. You can put some torque on the nut when holding the pulley properly. al zim 2018/10/25