Heya guys I need some help/input - I know there's been MANY posts here on related topics here, but none quite address my current situation, so here goes...

10/02 MCS, was stock prior to recent install of Alta CAI / Alta 17% Reduction Pulley & Belt / MTH

Since the pulley install I've had some intermittnet belt 'squeal' - On the first test run it started under load around 4000rpm, & was a constant 'screech' from there... but after a few minutes driving the noise became much quieter & it's onset was much later in the rev range. Now, after 70-odd km, the squeal begins around the 5500rpm range & is constant onwards from there.

The installer is currently attributing the noise to 'glazing' on the new belt, & is keen to give it total 150km or so to whether it persists.

So...

• Does this sound like belt slip? I'm assuming it is
  
• Does anybody have any bright ideas as to the list of possible causes of the noise [slip or otherwise]?
  
• What is the next step[s] from here? Is it reasonable to give it 80-odd more km to see if the issue persists.

One of my concerns is the belt, & whether it's simply not short enough, & therefore lacking tension...

The belt is a Gates/NAPA #060539, which is that which is recommended by Alta for the 17% pulley. The packet says it's 1385mm Outer Diameter [effective, internal length 1371mm], but the stock belt it replaced is 1388 [I presume this is an Outer Diameter, but it doesn't specify]. All the paperwork states this is the right belt for the job, but unless the stock belt is 1388mm effective/inner diameter [ie. longer Outer Diameter], than the new belt is only 3mm shorter than the OEM part it replaced!?

• Can somebody please explain the belt options for me... is the replacement from Alta indeed only 3mm shorter than stock!?
  
• Should I be gitting a shorter belt? Is it the likely problem, or will the tensioner usually take up the slack with a longer belt?
  
• Will a shorter belt [ie #060535] result in significantly shorter belt life?

Thanks :D

 

It's all in this thread;
https://www.northamericanmotoring.co...ight=gatorback

 

that was a good read. I noticed the NAPA 060539 has gone from 54 1/8 to 54 1/2 (1385mm). I have the 17% pulley and the NAPA 060539. No squealing. No slipping.

 

<SNIP>

i was full of it!

 

that something got on the belt, and it's glazed, so that it doesn't have as much friction as it should.

The only way to tell that is to take it off and look, or to replace it with the same one and see if the squeel goes away.

One other thing to do, is look at a stock S and see how far the tensioner is compressed. Springs have a linear force curve, so as the tensioner is more extended, it's pressing with less force (there are constant force spring geometries, but our tensioner doesn't use one).

Good luck, and let us know what you find!

Matt

 

EDIT:
Turns out the belt was simply too long [albeit apparently being the right Part #]
Tensioner was simply at the limit of it's travel. [see pic attached]
Fitted a 060535 6PK1360 tonight, I've got a full hole showing on the Tensioner bar & all is running sweetly


Thanks :D