What does the strain pulley do?
A travel belt tensioner is a pulley mounted on a spring system or adjustable pivot point that is utilized to keep tension on the engine belts. … Both are being used to keeptension on the engine serpentine belts to ensure that they can travel the various engine accessories.

How do you adapt a tensioner pulley?
Convert the adjustment bolt on the side, top or bottom of the pulley counterclockwise with the ratchet and socket before item belt is loose enough to eliminate. Tighten the tensioner pulley by turning the adjustment bolt clockwise with the ratchet and socket before belt is tight.
How do you know

A tensioner pulley courses the belt around the tensioner and allows the belt to spin while the tensioner maintains pressure against it. A failing tensioner pulley could cause power reduction and damage to your belt-driven systems. You could have a failing tensioner pulley if you hear any squeaking or squealing under the hood. Bearings on the pulley can degrade, causing noise and warmth. Pulleys are usually manufactured from either plastic or metallic, so verify the pulley itself for just about any damage aswell. At O’Reilly Vehicle Parts, we’ve tensioner pulleys designed for many vehicle models.

The computerized pulley tensioner has an internal spring-loaded mechanism that keeps the serpentine belt under frequent tension. Its design allows it to keep the serpentine belt taut, so that the other item pulleys rotate at the same rpm (revolutions each and every minute) while beneath the same safe pressure. Tensioner pulleys can also absorb moderate shock loads that happen when the air conditioner cuts on and off. As a constantly rotating element, the pulley tensioner can provide off some warning signs before failure.

Rust and Corrosion
The pulley tensioner sits exposed to the elements at the front end of the engine. Subjected to puddled water “splash-up,” with time the tensioner arm and pulley device can rust. Corrosion can freeze the computerized tensioner device or rot the shaft bearings, that will cause a frozen situation in the adjustment pressure. Without the correct tension, the belt can slide.
Debris Contamination
Rocks, gravel and other street debris could be thrown up in to the tensioner pulley grooves and jam the device. This can permit the serpentine belt to slip on the tensioner pulley and shed. Overheated pulley temp results, and eventually the serpentine belt will melt and snap off.
Pulley Tensioner Spring
The pulley tensioner spring inside the housing may become weak from age and repeated exposure to heat. This causes the belt to flutter and skip rather than maintaining a constant pressure on the pulley. Symptoms of a weak spring present as glazing on the lower of the serpentine belt, with an intermittent flickering of the dashboard’s charging mild indicator. Squealing or squeaking will always be observed at the belt position.
Pulley Wobble
If the tensioner pulley wobbles on its shaft, this means the inside shaft bearings have worn. This may cause a pulley misalignment. Awful bearings trigger an audible growling noise. The external ends of the serpentine belt will fray and stretch out the belt. Gradually the rubber belt grooves flatten out and cause significant slippage. An excessively wobbling pulley can toss the belt off, leading to all the equipment to quit functioning.
Lever Arm Freeplay
Some tensioner pulleys have markings on the casing that indicate the utmost range that the pulley can travel. If the lever arm of the tensioner rides under or over the designated mark, this implies a stretched belt or a lever arm which has jammed in a single position.
Pulley Misaligment
The tensioner pulley face must match to the other accessory pulleys with a parallel alignment. Placing a long, straightedge ruler against the facial skin of the tensioner pulley, and then flushing it against another item pulley, can measure the angle. Any off-position measurement indicates put on shaft bearings in the pulley housing.
Serpentine Belt Noise
A moderately worn serpentine belt gives off a constant squeaking noise during engine idle. Belts which have worn severely project a loud chirping or squealing appear. The cause points to a glazed, put on or cracked belt. Dried out or partially frozen tensioner pulley bearings could cause such noises by wearing out the belt prematurely.
Lever Arm Oscillation
A lever arm that repeatedly oscillates back and forth during idle or higher speeds means the the within damper mechanism in the tensioner pulley has weakened or broken. This triggers sporadic tension strain on the belt and will manifest itself with intermittent chirping noises.