Detroit Series 60 - New alternator question

Nope, my alternator is driven by two belts and a pulley on the timing case forward of the water pump. The fan hub is driven from the crank pulley with three belts, and the A/C compressor is driven by a pulley on the fan hub.

 

Just got back to the Altenator deal. Got 2 of these pulleys and went to the smaller one myself. Went 1/2" shorter on a webbed belt, man you weren't kidding on that adjuster. Ended up having to take out the adjuster bolt to slip on the belt then put it back in place, it shows about an inch of threads behind it and a bunch out in front so its in a good spot. I was really surprised though to see what shortening that belt so little would do , even with a smaller pulley. Sure do like the web belt setup, right now anyway, have to run it a couple more weeks to know for sure. Oh the second pulley? I always carry a spare Altenator with me and the nut is a **!!!** to get off in the field so for $25 problem solved, pulley is on nut torqued , unit ready and waiting.