Hey everyone. I've had the M7 pulley & JCW belt combo since I got Smacky about 4 years ago & I've had to live with the belt squealing during a cold start (4 hours or more) It gets worse when the temps drop. Its kinda embarassing for people to hear the loud squealing when it happens The funny thing is, whenever I change the belt, the squealing goes away but comes back maybe after a few weeks. Then disappears...then comes back again. Gone...back...gone...back. Yes, its been like that for 4 years now Oh, the squealing goes away after the engine warms up

I'm thinking it could be the belt but like I said, it comes and goes regardless of the age of the belt. I was also thinking that it could be that one of the pullies are misaligned but if that were true I should ALWAYS be getting the squeal, cold engine or not.

I'm stumped and want to solve this mystery that I've had to live with for years now Any suggestions?

 

If everything is spinning properly (not a bad pulley) then you have to figure, either you are using a stock belt which is a bit too big for a pulley, or your tensioner is bad. The belt size you want to be using is napa 4060535 (or jsut 60535...I forget). Really if the tensioner is original, replacing it is a good idea. Mine came out in pieces and it is a wonder it didn't cause issues.

 

When is the last time the belt was changed?

 

The jcw belt is kinda big for a 16% reduction....
The m7 pulley is also a bit of an olderdesgin....tends to have higher wear on the belts....it also was known to varry a bit in desgin...
If the alighnment is ok....you might try a goodyear gatorback belt...the ribs are different to reduce squeel...try the equivilent to the 535 length mentioned above.

 

Smacky has about 43,xxx kms on it, still on original tensioner. Due for a belt change soon (as recommended, I change belts every year) I have an extra JCW belt but the NAPA belt & tensioner are probably worth a shot. Anyone know a site selling it that accept's paypal? I don't have a U.S. credit card because I live all the way here in the Philippines

 

I would think that this is the issue, don't forget the JCW pulley that the belt is designed for is only a 12.xxx% reduction therefor slightly larger than the one you're using, just try one step smaller in belt size.

 

I think its worth noting that M7 recommends the JCW belt with their 16% pulley.

 

After a quick search, I came across:

http://crossbelts.com/serpentine/6ribkseries.html

I'm gonna try to source one locally first

 

The statement....whenever I change the belt, the squell goes away for a few weeks....kinda indicates the belt is ok till it stretches in.
the belt length is indicated in mm on the belt (non-us system)...so you might try one size smaller than the jcw....the regular is 1388mm, not sure of the jcw. A serch should find it for you.
Manfacturesof pullies early on suggested JUST THE 2 OEM belt lengths....there was worries that the non oem belts were not strong enogh....but eventually it was decided changing them yearly was a good way to prevent breakage, and get the correct length.
just as a new std belt is ok on a 15%, the jcw on the 16% is iffy...basicly almost no diff between that and a 17%....the 535 is perfect with the 17%..or a 15%..should be fine, esp with yearly changes....and the 535 lenth is very common in auto applications..more likly instock than the mini std length too!! Win...win!!

 

Concur with Zippy, use the 535...

 

Any updates?
Was it the tensioner or the wrong size belt?
I'm having the same exact problem, except I have the 15% pulley.

 

Hi, sorry I just noticed your reply. The tensioner was fine, I just switched to a smaller sized belt & the squeal went away. IIRC, I went with the belt recommended for 17% pulleys on WMW

HTH