Squeaking Belt

chdorsey · **Joined:** Tue May 18, 2010 11:26 am **Posts:** 21

Hi all,

I've got an '05 Liberty I bought last summer with about 35k on it. When I first got it, the serpentine belt was squeaking a bit so I replaced it and that pretty much solved the problem. Now, about 6k miles later, the squeaking is back. Do I need a new tensioner? How hard is it to swap that out? Any other causes for it? Thanks,

Chris

papaindigo · **Posted:** Tue Mar 08, 2011 2:50 pm

Probably although you might want to check the alignment of all the "pulleys" the belt runs across first. Both have caused me problems on other vehicles.

tonycrd · **Posted:** Tue Mar 08, 2011 2:57 pm

Check the alternator pulley. It's a decoupler, it has a little clutch inside and they are notorious for screeching noises.

Only thing you can do about it is replace it.

Snowy · **Joined:** Sat Jan 16, 2010 3:00 am **Posts:** 42

The only thing I would add is to start your vehicle without the belt attached.

I had "squeaking/chirping" noises and when the dealer went to replace the alternator we found that the squeaking was still there, even with the belt entirely off the motor. Turns out it was the timing belt making a chirping noise. The belt was fine, but there was no way to know without doing almost the entire job.

I am sure mine was a rare case, but as long as you have the chance, start it up and listen.

boilermaker2 · **Posted:** Wed Mar 09, 2011 12:09 am

This is not a repair to delay... :grim:

onthehunt · **Posted:** Wed Mar 09, 2011 10:27 am

Idler pully bolts are left-hand thread...

chdorsey · **Joined:** Tue May 18, 2010 11:26 am **Posts:** 21

Thanks for the advise. We're supposed to get hammered with rain here for the next 2 days, but I'll try removing the belt and see if I still get the squeaking noise.

Chris

boilermaker2 · **Posted:** Thu Mar 24, 2011 12:09 pm

How did it go?

chdorsey · **Joined:** Tue May 18, 2010 11:26 am **Posts:** 21

I was slammed last weekend and didn't have a chance to take the belt of to see if the squeak was still there, so I went the lazy route and bought a can of the serpentine belt conditioner. After spraying that on, the noise was gone for the rest of the day and has slowly started to come back in the past few days. I can only assume whatever friction additives are in that stuff were enough to mask things for a short while, but that I do indeed have a bad tensioner. Any advise on changing out the tensioner (besides the left hand threading, which will save me an hour of cursing - thanks onthehunt)?

Chris

racertracer · **Posted:** Fri Mar 25, 2011 10:59 am

you don't need a new tensioner, you need a new alternator decoupler which is making your tensioner fluctuate and is the cause of the squeek you hear.

You can go ahead and change all the $ parts you want that are connected to the serpentine belt, but if you don't change the root of the cause of the problem (the ALternator decoupler) the problem will not go away.

Remove the plastic cover off of the decoupler. The Decoupler sometimes has rust dust on it, visible when the plastic cover is removed and an indication that the decoupler has failed.

boilermaker2 · **Posted:** Fri Mar 25, 2011 11:05 am

racertracer wrote:

you don't need a new tensioner, you need a new alternator decoupler which is making your tensioner fluctuate and is the cause of the squeek you hear.

You can go ahead and change all the $ parts you want that are connected to the serpentine belt, but if you don't change the root of the cause of the problem (the ALternator decoupler) the problem will not go away.

Remove the plastic cover off of the decoupler. The Decoupler sometimes has rust dust on it, visible when the plastic cover is removed and an indication that the decoupler has failed.

x2

B2

tonycrd · **Posted:** Fri Mar 25, 2011 12:45 pm

x2 and the tensioner does not have left hand thread.

It's right hand. The idler wheels have left hand thread.

chdorsey · **Joined:** Tue May 18, 2010 11:26 am **Posts:** 21

Can you replace just the decoupler or do I have to get a new alternator? I didn't see it listed on Napa or Moparonlineparts.com.

Thanks for the advise.

Chris

racertracer · **Posted:** Mon Mar 28, 2011 1:58 pm

Just the decoupler..... the part number is in one of these posts somewhere along with how to remove it. Or ask your local Jeep parts department.

chdorsey · **Joined:** Tue May 18, 2010 11:26 am **Posts:** 21

Thanks, guys, for the advice. I am going to get on this ASAP. For posterity, here are some links to good discussions about replacing the decoupler:

viewtopic.php?f=5&t=47184
viewtopic.php?f=5&t=36743
viewtopic.php?f=5&t=44550
viewtopic.php?f=5&t=39287
viewtopic.php?f=5&t=53244

Chris

Squeaking Belt

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