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Wed Dec 19, 2012 8:06 am

1973 Super Beetle

Trying to tighten the nut on the brand new generator pulley I just bought, but it won't tighten. It just gets to a certain point and keeps spinning around. Any thoughts on how to get that internal piece to not spin. I need to tighten this bolt - my battery is uncharged! :(. Thanks

Wed Dec 19, 2012 8:17 am

Do you have the woodruff key in the generator shaft?

Wed Dec 19, 2012 8:29 am

No, I just use a screwdriver. No good?

Wed Dec 19, 2012 9:21 am

you didn't put this part in?

Wed Dec 19, 2012 9:23 am

I have a while bag full of those.. Where do they go?

Wed Dec 19, 2012 9:26 am

Is the entire generator spinning, or is it just the nut, or just the pulley?

If it's just the nut it may be stripped, check the threads.

If it's just the pulley make sure the woodruff key is installed. It's a small half circle of metal that keeps the inner half of the pulley secured on the shaft.

If it's the entire generator make sure your getting your screwdriver jammed in there right. It should wedge against a slot in the pulley and a piece of metal behind the pulley.

Wed Dec 19, 2012 9:35 am

Ok, thanks a lot. I think it's your 3rd option. I jut don't know how to install the woodruff key..

Wed Dec 19, 2012 10:25 am

http://www.thesamba.com/vw/forum/viewtopic.php?t=534498&start=0
One of many threads found with the search function :wink:

Wed Dec 19, 2012 11:08 am

I have a box of these, Doorman #3. 1/8". Doesn't seem to fit in the generator half - it's too big. Should it be able to slight right in to the 'notched up' part on the pulley? Or should the pulley be pushing the key out somehow? I think my problem is that I don't know exactly what the function of this little semicircle is! :-/

Wed Dec 19, 2012 11:13 am

you need to get a metric one? Maybe Ace hardware. The half circle goes down into the groove then the pulley groove slides over it. What happened to the original key?
I have extras if you can't find the correct one.

Wed Dec 19, 2012 12:01 pm

Really?? I bought these from JC Whitney. So it's supposed to slide into the groove easily? Thanks though! I'll see if I can find one locally first. Much appreciated!!

Wed Dec 19, 2012 12:07 pm

you might be able to file it to fit better depending on how much is off. it should be a" snug" fit
read thru these

http://www.thesamba.com/vw/forum/search.php?search...=titleonly

Wed Dec 19, 2012 2:07 pm

60ragtop wrote: you need to get a metric one? Maybe Ace hardware. The half circle goes down into the groove then the pulley groove slides over it.

The Ace Hardware near me has metric woodruff keys, but have no idea if they stock the correct size. I'm sure your previous pulley was installed using one, and likely you lost it because you didn't rotate the pulley so the woodruff key was facing up when you pulled the old one off.

So look real good on your engine tins, maybe it's under the crankshaft pulley on its tin.

Wed Dec 19, 2012 4:56 pm

ryanthonyb wrote: I have a box of these, Doorman #3. 1/8". Doesn't seem to fit in the generator half - it's too big. Should it be able to slight right in to the 'notched up' part on the pulley? Or should the pulley be pushing the key out somehow? I think my problem is that I don't know exactly what the function of this little semicircle is! :-/
The woodruff key fits into the slot in the shaft then the inner half of the pulley slides over the key. The key should be a tight fit (no play) between the shaft and pulley. The key prevents the inner pulley from spinning independent from the shaft. The pulley and shaft are now mated.

Here is the half-moon slot in the shaft.

Woodruff key installed (tapped lightly into the slot with a hammer):

Inner pulley with slot for woodruff key:

P.S. - don't forget to use 10 shims between the inner pulley and the outer nut. Some go between the pulley halves, some go between the outer pulley and the nut.

Wed Dec 19, 2012 9:36 pm

Thanks so much. I now get it. Now, I guess I'm wondering why the key isn't built in to the shaft, as opposed to being a separate, wandering, inexpensive steel object... But who am I - I'm sure Ferdinand and his crew had it all sorted out. Thanks a lot - hoping to make a makeshift woodruff in the meantime as I wait for fellow Samba member to so graciously send me a spare key. Cheers :)

Thu Dec 20, 2012 3:27 am

Probably in case the woodruff key were to strip out, rounded over, break, etc. The replacement piece would only cost you about 10 cents instead of a new or rebuilt generator/ alternator.

Thu Dec 20, 2012 4:06 am

ryanthonyb wrote: ... Now, I guess I'm wondering why the key isn't built in to the shaft, as opposed to being a separate, wandering, inexpensive steel object... .

As a machinist with 50 years of experience I can tell you that making a shaft with the key from one piece would be a nightmare and next to impossible to do in the age before CNC and EDM technology.
Turning a shaft is quick and easy.
Cutting the key seat is quick and easy.
Making woodruff keys is quick and easy.
Woodruff keys are very common because they are practical.

Finally, get the correct key! Don't file one down and don't hard hammer one into the slot. The key should go in with just light taps from a SOFT hammer. If you don't have a soft hammer, use a piece of wood to prevent raising a burr on the key.

Look for you old key in the tin as Cusser pointed out.