Can't find alternator pulley for my car....

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I've got a rattle coming from the alternator pulley on my vehicle. 2009 Lacrosse with the Series III 3800.

If possible I'd rather replace the pulley instead of the whole alternator, I don't see any need to drop $125 on a whole new alternator when it still operates just fine.

Here's the only info I can find on the pulley. http://www.rockauto.com/en/moreinfo.php?pk=3572820&cc=1442771&jsn=248

I'll accept a junkyard part, just don't see how I'd be able to remove the pulley without an electric or air powered impact.
 
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Without a more mechanically complicated decoupler pulley (that your car's alternator apparently does NOT have), how/why would a regular solid belt pulley make a rattling noise beyond coming loose? It's not a wear item or something prone to going bad.
 
Most likely because I've been beating the [censored] out of it recently.....

I replaced the battery in March when the rattle first started occurring, I had both battery and alternator tested and the alt checked out.
 
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Car with the right foot. Driving like an idiot. I edited my last post for more detail. Rattle has been present for 4.5 months and the alternator checks out. Also probably doesn't help that I've been driving around on a busted motor mount.
 
There are a couple of alternator/starter part website that sells alternator pulley.
If all else fail, check ebay.
You need to know the diameter of the pulley plus no. of groove.

You CANNOT search by the alternator for your model car since you are looking for parts of the alternator.

I am not sure if the pulley alone will cost you more than the alternator itself or not much more if you buy a complete alternator.

Another way is to buy a used good one from JY.
 
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Pulley OD = 62 mm

Serpentine belt = 90.5" long by .82" wide with six ribs
 
Any alternator rebuild shop can help.

I have had good luck with eBay alternator pullies.

Yes, an impact is needed to change it.
 
I cant think of how a solid pulley would rattle unless its loose on the shaft. I would suspect a bearing going bad more than the pulley.
 
I've got no squealing or screeching noises. It's specifically a metallic rattle coming from the top of the engine/alternator pulley.
 
Originally Posted By: Trav
I cant think of how a solid pulley would rattle unless its loose on the shaft. I would suspect a bearing going bad more than the pulley.

This. ^

Or a belt idler pulley being the real culprit. Or the belt tensioner. Or the water pump. Etc.

Have you actually removed the belt and poked around to determine for sure it's the alternator? I just can't see how a sold pulley goes bad or how a rattling/loose pulley would be the pulley's fault.
 
Take the belt off and start the car to let it run for a few seconds, see if the noise is still there.

And you can turn the pulley by hand to feel for a bad bearing or movement. Solid, one piece pulleys don't go bad.

I thought my PS pump was going bad, turned out to be the AC clutch bearing. But until I removed the PS pump belt I could not tell.
 
Just fired her up, no rattle but I did hear a squeaking from the a.c. compressor that went away after about a minute. Tensioner has slight movement but is in sync with the back and forth movement of the engine due to the bad motor mount.

Ill have to replace the mount and go from there.
 
Originally Posted By: Trav
I cant think of how a solid pulley would rattle unless its loose on the shaft. I would suspect a bearing going bad more than the pulley.


I'm responding to this thread believing he has an "overrunning clutch" alternator pulley.
 
It allows the alternator to freewheel after letting off the accelerator.

Like this:
80_578_388_oap065.gif
 
I've literally watched the alternator pulley bounce around, and there is no bearing noise. No low or high pitched squeal/growl, just a faint
rattle. It's also intermittent. The charging system shows no signs of any kind of issue.

I'll check for play when I install the new motor mount, going to go the poly route since the 3.8's have weak mounts to begin with.
 
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Originally Posted By: Trav
I cant think of how a solid pulley would rattle unless its loose on the shaft. I would suspect a bearing going bad more than the pulley.


I have heard of the harmonic balancer on a 3.8l coming apart & ratteling . But that is at the bottom of the engine .

Were it me , I would remove the alternator & do a through visual & " rattle " test . And have a source / vender located , in case the alternator needs replacing .

God bless
Wyr
 
if the pulley is rattling or wobbling, it is a decoupling pulley. They are easy to change, it should cost ~$50-60, and you'll need a $10 kit to change it. Much cheaper than getting the whole alternator, which often come with a solid pulley, which can cause the serp belt to jump if doing a hard acceleration on a vehicle designed to have a decoupler pulley. While it's another level of complexity, they allow you to run a lighter belt tension which lengthens belt and accessory bearing life. Sounds like you need to go a little further to isolate the noise. remove the belt and start poking around. good luck.
 
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