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Serpentine belt length options?

xcntrk

Bronco Guru
Joined
Jan 12, 2012
Messages
2,473
Loc.
NOVA
I seem to be having an issue with my serp belt being slightly too long and my PS pump is squealing a bit. The belt I’m using appears to be the proper length and for the most part is “snug” but definitely not tight. I noticed that the tensioner is just barely engaged in adding additional tension. What are my options for a shorter belt? Ideally I just need a few mm shorter to tighten things up and get more pressure from the tensioner.

The belt I’m using is 6PK2210/870K6 which according to Amazon is a 6 Ribs x 2210 mm or 6 Ribs x 87 Inch. This is installed on an Explorer serp setup using all factory pulleys and pside bracket, but with an aftermarket (WH) driver-side bracket setup for a Saginaw pump. I think the culprit here is the pulley on my Sag pump. I got it from WH and it’s labeled PSC and appears to be a bit undersized (overdriven?). This is likely causing the additional excess in belt length. All these components are new including tensioner.
 

Timmy390

Contributor
Bronco Guru
Joined
Jan 1, 2011
Messages
5,759
Loc.
Conway, AR
You should be able to go to any parts store and get the length you need. If 87 is a bit too long, go get a 86 inch. Still too long, get an 85. I think you can even get some belts in 1/2 inch increments but I'm not positive on that.

I test fit 3 belts before finding the length I needed on my 351W with air pump removed.

Tim
 
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xcntrk

xcntrk

Bronco Guru
Joined
Jan 12, 2012
Messages
2,473
Loc.
NOVA
You should be able to go to any parts store and get the length you need. If 87 is a bit too long, go get a 86 inch. Still too long, get an 85. I think you can even get some belts in 1/2 inch increments but I'm not positive on that.

I test fit 3 belts before finding the length I needed on my 351W with air pump removed.

Tim

That's great feedback! I had no idea they were available in such a selection of lengths. I found one 3/16" shorter and 9/16" shorter. I went with the 9/16" should give me slightly over a half inch of lesser length. Thanks!
 

cbford

Jr. Member
Joined
Mar 30, 2005
Messages
77
You can search them up in the interwebz too. I found that your part number - 870k6 - was the length and rib designation. So, 86.5 inch is 865k6. 85 inch is 850k6.

I had a goofy size pulley too. So with all accessories on engine, I stretched a tape measure around the path to measure. Then searched for nearest size I thought would work.
 

sanndmann3

Contributor
Bronco Guru
Joined
Jun 13, 2007
Messages
1,796
buy 3 or 4 different sizes and take back the ones you don't use... thats what i found works best...
 
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