I posted this question on the Samba as well; sorry to anyone who has to read this twice- no answers on the Samba so far.

(This is on my '84 stock 1.9, but don't all the alternators on both 1.9 and 2.1 mount the same way?) 

I needed to tighten my alternator belt. I have a problem with the lower pivoting bolt- the one under the alternator. I removed the alternator from my spare engine to see the set-up. It's a carriage bolt with a square shoulder. I suspect that the square shoulder or the hole it sits in has rounded, as when I turn the nut at the rear and under the alternator the bolt spins as well and won't tighten or loosen. 

I didn't look so closely at the spare engine to see how that mount is attached to the engine, but I'd rather not have to take that off. I'm wondering if there is enough room back there to put a standard bolt with a hex head. I know there's room to get the bolt in, because obviously the carriage bolt slides in and out, but I'm wondering about room for a socket to hold it in place. 

The nice thing about the original is that it sits in place while you tighten the nut on the other end. 

Anyone else have this problem and found a solution? As I said, the other threads seem to deal with one of the other two bolts or the bracket that the alternator locks onto. 

Thanks, 
Ed