What does the strain pulley do?
A travel belt tensioner is a pulley mounted on a spring mechanism or adjustable pivot point that can be used to keep tension on the engine belts. … Both are being used to keeptension on the engine serpentine belts in order that they can drive the various engine accessories.
How do you change a tensioner pulley?
Change the adjustment bolt privately, top or bottom level of the pulley counterclockwise with the ratchet and socket before item belt is loose enough to remove. Tighten the tensioner pulley by turning the adjustment bolt clockwise with the ratchet and socket until the belt is tight.
How do you know
A tensioner pulley guides 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 high temperature. Pulleys are usually made of either plastic or steel, so check the pulley itself for just about any damage as well. At O’Reilly Vehicle Parts, we have tensioner pulleys available for many vehicle models.
The automatic pulley tensioner comes with an internal spring-loaded mechanism that keeps the serpentine belt under continuous tension. Its design permits it to keep the serpentine belt taut, to ensure that the other equipment pulleys rotate at the same rpm (revolutions each and every minute) while beneath the same safe pressure. Tensioner pulleys can also absorb slight shock loads that happen when the air conditioner cuts on / off. As a continuously rotating component, the pulley tensioner can provide off some indicators before failure.
Rust and Corrosion
The pulley tensioner sits exposed to the elements at the front end of the engine. Put through puddled water “splash-up,” with time the tensioner arm and pulley device can rust. Rust can freeze the automated tensioner device or corrode the shaft bearings, that may cause a frozen location in the adjustment pressure. Without the proper tension, the belt can slip.
Debris Contamination
Rocks, gravel and other highway debris can be thrown up into the tensioner pulley grooves and jam the system. This can allow the serpentine belt to slip on the tensioner pulley and burn off. Overheated pulley temperatures results, and eventually the serpentine belt will melt and snap off.
Pulley Tensioner Spring
The pulley tensioner spring inside 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 demonstrate as glazing on the lower of the serpentine belt, with an occasional flickering of the dashboard’s charging mild indicator. Squealing or squeaking will be noticed at the belt position.
Pulley Wobble
If the tensioner pulley wobbles on its shaft, this means the interior shaft bearings have worn. This may cause a pulley misalignment. Bad bearings trigger an audible growling noise. The outer ends of the serpentine belt will fray and stretch out the belt. At some point the rubber belt grooves flatten out and cause key slippage. An excessively wobbling pulley can toss the belt off, causing all the gadgets to quit functioning.
Lever Arm Freeplay
Some tensioner pulleys possess markings on the housing 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 up to the other accessory pulleys with a 
parallel alignment. Placing an extended, straightedge ruler against the face of the tensioner pulley, and flushing it against another accessory pulley, can measure the angle. Any off-position measurement indicates worn shaft bearings in the pulley housing.
Serpentine Belt Noise
A moderately worn serpentine belt produces a constant squeaking noises during engine idle. Belts which may have worn severely task a loud chirping or squealing appear. The cause details to a glazed, worn or cracked belt. Dry or partially frozen tensioner pulley bearings can cause such sounds by wearing out the belt prematurely.
Lever Arm Oscillation
A lever arm that repeatedly oscillates backwards and forwards during idle or more speeds means the the within damper mechanism in the tensioner pulley has weakened or broken. This triggers sporadic tension pressure on the belt and can manifest itself with intermittent chirping noises.