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Old 09-11-2010, 04:31 PM   #1
jb1016
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tensioner pulley adjustment

Hey guys, I'm getting a rattle out of my serp belt tensioner. I can see the source of the rattle -- as the arm pivots back and forth with the pulley, it clack-clack-clacks against the base on the left side. I know that's a terrible description; maybe I'll try posting a video later.

Has anybody else had this happen? The tensioner doesn't appear to be adjustable at all. Is there any fix short of taking a grinder to it for some clearance? Thanks in advance.

Oh, and by the way the tensioner is less than a year old, as is the belt. The rattle started about the time I put in a new alternator, maybe a month ago.
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Old 09-11-2010, 07:21 PM   #2
bwood
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Re: tensioner pulley adjustment

If the tensioner is bouncing around, it can be a few things:

-Worn tensioner
-Stretched belt
-An accessory (alt or compressor) near the tensioner causing excessive drag

The tensioner has an arrow and some marks on it, if the arrow is on the marks to the less tension side, it points to a stretched belt. If the arrow lines up with the marks to the more tensioned side of the scale the belt is probably good. The tensioner is not adjustable.
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Old 09-11-2010, 09:53 PM   #3
scotts62
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Re: tensioner pulley adjustment

Could be a bad one, warranty on it maybe? I havent bought one in a while..
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Old 09-12-2010, 07:23 AM   #4
Zeke
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Re: tensioner pulley adjustment

I agree with bwood and would take the belt off and check the accessories to make sure you don't have a bearing going out. Also check the harmonic balancer to make sure the rubber hasn't broken loose. The tensioner will bounce in time with what ever is catching making you think it is bad.
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Old 09-13-2010, 12:55 PM   #5
jb1016
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Re: tensioner pulley adjustment

Quote:
Originally Posted by bwood View Post
The tensioner has an arrow and some marks on it...
I can't find these marks. Are they supposed to be visible with the tensioner in place? It may be an aftermarket unit (can't remember); so maybe it doesn't have any marks.
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Old 09-15-2010, 09:23 PM   #6
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Re: tensioner pulley adjustment

OEM tensioner pulleys are solid steel and have a rubber bushing. They also have a raised groove on the edges to keep the belt centered

The aftermarket tensioner pulleys I have seen are aluminum, are flat around the outside, and have an actual bearing in the center for the pulley to ride on.
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