Here is a fairly decent explanation: Denlors Auto Blog » Blog Archive » Overrunning Alternator Decoupler – Clutch Type Alternator

Hey guys thanks for the replies. I was able to replace the pulley and belt easily and was hoping that would be the end of this thread however my car wont start now. I believe i installed everything correctly which is why i'm confused since it started even with the belt off.

I thought maybe the battery just died since its been sitting there for about a week, but whenever i hooked it up to my girlfriends car and charged it for about 10 minutes it still wouldn't start. Here's a video of me turning on the car. Here's a video of me trying to turn it on.

https://drive.google.com/file/d/1pedxsov6gcxEBjGwx9SAqkr_97ZAOxqX/view?usp=sharing


My 00' boxster has a little over 100K miles, i'm willing to change the alternator and agree that i probably should. Could this new problem be related to the alternator?

Thank you guys for the help!

Hey JFP in PA..I thought this cap was some sort of dust cover. Are you sure it isn't needed? I am in the the middle of replacing mine as we speak and my Bosch part did not include the cap as well.

This actually happen to me last week. I heard a bit of squeaking from a the pulley and was going to check it over the weekend. Didn't make it cause the following day I actually heard someimg fly off and down the road and lost powering steering. I had towed and it turns out the alternator pulley came off. This alnerator has 150,000 miles on it :)

The cap is a dust/debris shield to keep crud out of the inner workings of the pulley.

Thats what I thought. My replacement pulley did not come with one and I lost the orgininal. Can this part be purchased separately? I did a search and came up with no luck.