Serpentine belt

**derekbuckner1** · 07-31-2011, 10:21 PM

If I take the car up towards 6k rpm my serpentine belt likes to slip off the tensioner. Not completely throwing the belt but it kicks over about half an inch off the pulleys.

Any advice?

Adjustable tensioner? I was told some other ls tensioners had taller walls on the pulley, not sure if that's true or not.

**blackcar** · 08-01-2011, 07:19 AM

Is the tensioner bad?

**pajeff02** · 08-01-2011, 08:20 AM

Take a look at this: http://www.ls1.com/forums/showthread...belt-tensioner

I would check all your pulleys with the belt off to ensure that nothing is loose and that they all run true. Also, take a look at your balancer to ensure that nothing is askew.

**Knight** · 08-01-2011, 08:24 AM

^This. You may also want to check the spring tension on the tensioner. They will wear and not hold as they should too.

**derekbuckner1** · 08-01-2011, 08:42 AM

Thanks guy. How do I check the tensioner to see if it is bad? And thanks Jeff. I'll try to look into a katech tensioner. It doesnt happen often now I was just wanting to find a fix before I (hopefully) swap my cam this winter and crank a little higher rpms.

**blackcar** · 08-01-2011, 10:15 AM

Originally Posted by derekbuckner1

How do I check the tensioner to see if it is bad?

With out the motor running, you can put a wrench on the tensioner and see if it is hard to move. Mine was completely shot so it was easy to tell. But I've had one in the past that I thought was good, but a mechanic told me it was bad. They should be pretty tuff to move. Or see if you have any slack in your belt. I think +/- a half inch.

**derekbuckner1** · 08-01-2011, 01:18 PM

Originally Posted by blackcar

With out the motor running, you can put a wrench on the tensioner and see if it is hard to move. Mine was completely shot so it was easy to tell. But I've had one in the past that I thought was good, but a mechanic told me it was bad. They should be pretty tuff to move. Or see if you have any slack in your belt. I think +/- a half inch.

No slack. Belt is tight. As is the tensioner. I have to put a socket on it every time that it kicks forward and it's not easy to move.

**blackcar** · 08-01-2011, 02:34 PM

Then this

Originally Posted by pajeff02

Take a look at this: http://www.ls1.com/forums/showthread...belt-tensioner

I would check all your pulleys with the belt off to ensure that nothing is loose and that they all run true. Also, take a look at your balancer to ensure that nothing is askew.

**whitetrashbird** · 08-01-2011, 03:03 PM

Sometimes when the belt tensioner is getting bad, it will actually kick out of alignment. I would guess yours is just starting to get bad, thus why it's only doing it at higher rpms. It will get worse and eventually keep kicking the belt off. New belt and tensioner should fix it.

Dan

**sjsingle1** · 08-01-2011, 03:06 PM

http://www.ls1.com/forums/showthread...nstall-in-pics

holy read my mind batman !!!!

**cammed goat** · 08-01-2011, 03:41 PM

I agree with all of the above. Wobbly crank pulley, worn/crooked tensioner will cause the belt to slip/fall off. Keep us posted.

**derekbuckner1** · 08-01-2011, 09:45 PM

I'll look into all the above this weekend when I get the time to do so. Thanks again for all the advice. I will post up anything I come up with

**KMdef9** · 08-01-2011, 11:41 PM

Go with a gatoback belt!

**derekbuckner1** · 01-11-2012, 07:49 PM

hate to bring this thread back to life, but the belt trouble didnt happen for a long time. When i started the car earlier this week, the belt whined like crazy. it was on track as it should be. i have a katech tensioner and a gatorback belt in the mail and will let you guys know if it fixes the problem

**KMdef9** · 01-11-2012, 09:07 PM

It def. should.

**derekbuckner1** · 01-12-2012, 06:22 AM

Originally Posted by KMdef9

It def. should.

I sure hope so. I'll take a look at all the other pulleys when I take the belt off

**KMdef9** · 01-12-2012, 09:49 AM

Are you replacing both belts?

**derekbuckner1** · 01-13-2012, 03:33 AM

Yeah. The belt I ordered originally was the ac belt. Summit racing had it listed as the serp belt and was the only one they had. Now I have the ac belt and have to find the serpentine belt elsewhwre

**watman02** · 01-16-2012, 10:55 AM

if you can i would not use a gator back belt I have had maney of them come back into the shop after being installed for squeeling and chirping. mostly on fixed tensioner cars though. i prefer gates belts jmho

**derekbuckner1** · 01-17-2012, 04:03 AM

Originally Posted by watman02

if you can i would not use a gator back belt I have had maney of them come back into the shop after being installed for squeeling and chirping. mostly on fixed tensioner cars though. i prefer gates belts jmho

This one has already been ordered. I saw many mixed reviews on the belt before placing my order and it seemed like many people loved them. If I have issues with it I will give gates a try. I've never used a cross hatched belt like the gator back before, but I thought I would give it a try