Replacing Worn Alternator Pulley Serpentine Belt

These are typical pulleys that run a serpentine belt on a Leece Neville alternator. The alternator pulley on the right is the original and is worn on the top edges of the pulley grooves. They are flattened out from belt wear which tells you how durable today's serpentine belts can be.

Of course we launced a campaign to replace the pulleys on the other buses spec'd with the same alternator. Click on the picture above for a closer look (if you could hold these pulleys in your hands you would see the wear much clearer)

The alternator puts out 160 amps so there will be a substantial load on the pulleys and the belt. The engine is a Cummins ISC which uses a tensioner pulley. If this pulley was left on any longer there very well could have been belt slippage eventually. Most mechanics (myself included) would not notice this wear especially during an alternator replacement.

We looked a little closer in this case because of a recurring charging system problem. That's what happens when you look a little deeper into a stubborn mechanical problem.