Well this was a first for me.
short local trip and all the sudden the gear shifter starts making the strangest rattle on acceleration.
pulled over piped the engine lid only to find this.
fortunately I had a spare back at the house so a quick rescue trip from the wife and I was back up and running.
any one know what might have caused this to fail?
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Yeah, two things:
You could try looking at Bug City or some site like that for a real German pulley, but be prepared for serious sticker shock.
https://www.bugcity.com/shop/shop.lasso?pquery=pulley
Apart from that, try to find a heavy duty or at least beefy pulley from the usual suppliers.
Asian Fans are like that, too - They tend to rip the center of the fan apart because of too-thin metal used making them weaker.
There's a process for tightening the pulley and fan belt that requires a number of shim washers to be used between the two halves of the pulley. You add shims to make the belt looser and remove shims to make it tighter. How many used is up to the pulley diameter and the length and thickness of the belt.
Using the right number of shims to get 3/8" - 1/2" deflection at the middle of the belt when adjusted correctly is very critical! See a VW service manual for 1970 or so for more details.
I'm running an OT pulley and it is very robust. Pricey but worth it. Out of stock at ISP but you might be able to find it somewhere else.
Yeah, unfortunately there are poorly made alternator/generator pulleys that break out there and it's hard at a glance to tell the difference, so I guess the best thing is to be prepared with a spare (carried in the car) with the tools to replace it.
Robert meant to do that......
Has anyone used one of the billet aluminum alternator pulleys available from CB?
Thanks guys the offending pulley came from pelican parts. It’s the 356 smaller than the VW one.
mid anyone knows of a source for high quality 356. Pulley please let me know.
Email Adam Wright at Unobtanium at
I'm certain they'll have a very good, used, original 356 pulley. I have no idea what they'll charge for it, but it should be a good one.
@LI-Rick posted:Has anyone used one of the billet aluminum alternator pulleys available from CB?
I'm running one of their billet pulleys. I like it, but their pulley nut is also aluminum (when I bought it). Mine started to strip after a few years so I switched the nut to a steel one I had on hand. No over torquing on my part.
@Michael Pickett, Thanks. I guess I could always spin up a nice nut out of stainless.
I made this head nut for a 1939 Servi-Cycle that I’m currently restoring.
@LI-Rick posted:@Michael Pickett, Thanks. I guess I could always spin up a nice nut out of stainless.
I made this head nut for a 1939 Servi-Cycle that I’m currently restoring.
Amazing. Like I said earlier, I don't wish I could do work like you can, but I do wish you lived next door to me 😄
@Michael Pickett, thanks for the kind words. I just wish I had a clue about electrical work!
Rick, I am available to help with electrics. If you feed me and give me a place to sleep in the barn, that is.
Danny, I’ll keep you on speed dial! 
