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Kit Masters Part #638667-1 - Replacement for OEM Part #s: FLT6386671 Kit Masters Part #638667-1 - Replacement for OEM Part #s: FLT6386671 Kit Masters Part #638667-1 - Replacement for OEM Part #s: FLT6386671 Kit Masters Part #638667-1 - Replacement for OEM Part #s: FLT6386671
Kit Masters Part #638667-1 - Replacement for OEM Part #s: FLT6386671 Kit Masters Part #638667-1 - Replacement for OEM Part #s: FLT6386671 Kit Masters Part #638667-1 - Replacement for OEM Part #s: FLT6386671 Kit Masters Part #638667-1 - Replacement for OEM Part #s: FLT6386671
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PolyForce™ Belt Tensioner

Kit Masters Part #
638667-1

PolyForce™ Belt Tensioners by Kit Masters replace the traditional spring with a longer-lasting, Polymer Torsion Core. They also feature upgraded pulley bearings to drastically extend the life of the belt tensioner.

*Mounting hardware not included

2 Year/200,000 Mile Warranty



ENTER POSTAL CODE TO SEE PRICING:

No Springs Attached

Conventional belt tensioners use springs to hold their position and tension. However, springs can only flex so many times before they fail. PolyForce™ Belt Tensioners replace this spring with a longer lasting, new and unique Polymer Torsion Core. A compressed silicone replaces the spring, thereby eliminating the primary cause of failure.

PolyForce™ Belt Tensioner
PolyForce™ Belt Tensioner

Improved Bearings

The other common failure point in a belt tensioner is the bearing. The pulley bearing absorbs a huge amount of vibration and can often fail too soon. PolyForce™ Belt Tensioners have dramatically improved pulley bearings to give them extended life. Our bearing is designed specifically for pulley applications and features:

– Outer Ring Rotation

– Anti-Vibration Grease (won’t separate)

No Spring = Less Heat

To demonstrate the difference between tensioners, we ran a PolyForce belt tensioner and a competitor’s belt tensioner along an oblong pulley, which causes it to flex back and forth.
After 20 minutes the competitor’s belt tensioner was 62.5% hotter than the PolyForce belt tensioner. Less heat leads directly to longer lasting components and assists in achieving lower under-hood temperatures.

PolyForce™ Belt Tensioner
 

Replaces OEM Part #:

FLT6386671,

 

California Residents: Prop 65 Warning

Hub Bearings Required

You are purchasing a Kysor-style fan clutch. When replacing a Kysor-style fan clutch, you must always replace the hub (pulley) bearings at the same time. Failure to do so will void the warranty on your fan clutch.

To determine the required bearing kit for your hub, enter the hub part number in the search field below, find the part number of the bearing kit you need on the dropdown below, or click on the 'Learn More' link below.


Choose Your bearing kit (if known)

I don't want to purchase a hub bearing kit at this time.
Failure to install new hub bearings with your clutch will void your warranty.

Core Return

This product includes a core charge. You may pre-pay for the freight to return your core during the checkout process, or ship using your own method. Core returns must be received by Kit Masters within 30 days of purchase.

Would you like to pre-pay for the return freight?

Yes, I want to pre-pay for Core Return Freight.
$1,337.00

YES

No, I do not want to pre-pay for Core Return Freight.

NO