Alternator Pulley sheared off!?!
 

Was driving my '00 boxster today when i lost my power steering and both the ABS and battery light came on. luckily i was close to home. Did some quick research, it seemed like it was just a serpentine belt that needed to be replaced.

Open up the back compartment to put a new belt in and saw that the belt slipped off and it seemed like it was in good condition. I inspected the pulleys and saw that my alternator pulley had sheared off!? A part of the pulley is still connected to the shaft it seems.

Here are some pictures:

https://imgur.com/gallery/3EqtE


Is this normal? I've looked throughout the forums and haven't seem a similar occurrence happen? Should i replace the alternator as well?

Thanks in advance!:cheers:

Um, no. That is not normal. But, from the looks of it, that thing was rusted badly. I can't believe it wasn't making some crazy howling noises. All the red stuff is rust. That pully was seized. The $100,000,000 question is why was it so rusty in the first place? That requires moisture, which there shouldn't be much of in that part of the engine compartment. If I were you, replace the alt and EVERY other rotating thing on the engine, to include the water pump, idler pullies, even possibly the power steering pump. It is possible every one of these items has rust, which is bad. At the very least, closely inspect all of these for ANY sign of rust and replace as necessary.

That pulley is completely normal. It is a declutching style pulley, the only thing missing is the snap on plastic from cover, which is decorative:
http://986forum.com/forums/uploads01...1342316421.jpg http://www.oldbenz.co/content/images...00860_550.jpeg

If the alternator is not making ratcheting sounds, put a new belt on it and you are done.

You seemingly have no clue what you're talking about

Scroll down to the next pic.

The next pic:

http://986forum.com/forums/uploads02...1515593996.jpg

Seems the alternator clutch pulley seized
It looks like you can buy just the alternator clutch pulley for around $40
That does seem odd that much rust is up there. Maybe the water pump is leaking onto the belt?
Don't think you need to immediately jump to replacing all spinning things BUT you should spin and listen to see if any others are coming to their end of life

You may want to replace the belt as well

If the alt. clutch had seized, wouldn't the alternator still turn? Does the alternator turn easily and smoothly?

I don't think I'd buy a new alt. clutch before I answered these questions. More likely I'd look for a reman'd alternator. And check out the operation of all the other rotating thingies on the front of the engine.

Yikes, that's not what i was hoping to hear. I did inspect the other pulleys and components back there - didn't see any rust and they all do spin freely. Maybe the pulley somehow got rusted and when it seized the rust blew onto the alternator????

The alternator does spin easily and freely. I ordered a new alternator pulley and alternator tool (CTA Tools 8088 Bosch Alternator Wrench). Hopefully that's all that's needed.

Thank you guys for the help! really appreciate it!

Don't pay much attention to Geof3's post, there isn't much good information in it.

From your picture, it doesn't look like rust, it looks like a red dust, which would make me suspicious of a bearing starting to fail. It could be the pulley bearing, or a bearing in the alternator itself. If it were me, I'd play it safe and just replace the entire alternator.

I had the same thing happen a while ago, except the pulley shaft sheared off.
Car overheated and fortunately did not cook anything other than the hose coming from the oil cooler. Mechanic replaced it and all is well. It's a potential engine killer though if I wasn't paying attention.

Its not normal. Normally, the belt fails or the alternator bearing fails or the voltage regulator fails.


If it were me, I'd replace the entire alternator. Mostly because I value reliability over cost. You don't say how many miles the car has, but I'll guess that it has enough miles that I wouldn't want to take the chance that the bearing or voltage regulator will fail in a short time and then you'd have to do a second repair on the same component. Since labor is typically 40%-60% of a repair cost, saving money on the parts replaced sometimes isn't the cheapest route. And even if you DIY it, no one wants to replace an alternator in a Boxster more than once.

You guys obviously didn't see the pic where the pully was sheared clean off the spool? I am fully aware the pully is a clutch type.

And where would "red dust" come from? Other than a rusted/worn bearing/surface? That pully is NOT normal. Sorry.

As mentioned, the pully is replaceable with a special tool. If there are no further signs of corrosion or otherwise, it should be fine. (though thstone's advice is spot on)

NO DOUBT about that! That bolt/bushing can be a major BIOTCH!

Sorry, but we see about 20 or so that look like this every week and they are both serviceable and completely normal (OP's original photo):

https://i.imgur.com/3854uCC.jpg

They all throw some red dust, which is probably why Porsche put the plastic cover on them in the first place.......

JFP, have you still not seen the picture with the pulley sitting in his hand? The pulley sheared off the spindle. The race is actually broken. You are only looking at the first picture...

I was under the impression that the one being held in a hand is not by the original poster, it is from someone else, but if that is the OP's pulley, then it has failed.

That doesn't change the question about the pulley's emitting some rust, they all do that to varying degrees.

hey - fooled me too initially, but if you follow the link to the OPs imagur account and scroll up on the pic that appears you will get a bunch more pics, including those posted by others later in the thread. the OPs pulley did in fact come right off.

I reposted a screen shot of the subsequent images so I wouldn't make the thread unreadable with a SUPER SIZED IMAGE.

Thanks for all you do, but in this case, I think you missed it originally.

Yes, those who have done this job, know exactly what I was talking about! :cheers:

What is the purpose of the alternator having a clutch?

Does it engage under computer control or is it static?

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.