What does the strain pulley do?
A drive belt tensioner is a pulley mounted on a spring mechanism or adjustable pivot point that is utilized to keep tension on the engine belts. … Both are used to keeptension on the engine serpentine belts in order that they can drive the many engine accessories.
How do you modify a tensioner pulley?
Switch the adjustment bolt privately, top or bottom of the pulley counterclockwise with the ratchet and socket until the equipment 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 I know
A tensioner pulley guides the belt around the tensioner and allows the belt to spin as the tensioner maintains pressure against it. A failing tensioner pulley could cause power loss and harm to your belt-driven devices. You could have a failing tensioner pulley if you hear any squeaking or squealing under the hood. Bearings on the pulley can wear out, causing noise and temperature. Pulleys are usually made of either plastic or metallic, so check the pulley itself for any damage as well. At O’Reilly Automotive Parts, we have tensioner pulleys available for many vehicle models.
The automated pulley tensioner has an internal spring-loaded mechanism that keeps the serpentine belt under regular tension. Its design enables it to keep carefully the serpentine belt taut, so that the other accessory pulleys rotate at the same rpm (revolutions each and every minute) while under the same safe pressure. Tensioner pulleys may also absorb moderate shock loads that happen when the air conditioning unit cuts on / off. As a regularly 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. Put through puddled water “splash-up,” as time passes the tensioner arm and pulley system can rust. Corrosion can freeze the automated tensioner device or rot the shaft bearings, which will cause a frozen posture in the adjustment pressure. Without the proper pressure, the belt can slip.
Rocks, gravel and other highway debris can be thrown up in to the tensioner pulley grooves and jam the system. This can permit the serpentine belt to slide on the tensioner pulley and melt away. Overheated pulley temperature results, and eventually the serpentine belt will melt and snap off.
Pulley Tensioner Spring
The pulley tensioner spring in the housing may become weak from age and repeated contact with heat. This triggers the belt to flutter and skip instead of maintaining a constant pressure on the pulley. Symptoms of a fragile spring present as glazing on the lower of the serpentine belt, with an intermittent flickering of the dashboard’s charging light indicator. Squealing or squeaking will be heard at the belt position.
If the tensioner pulley wobbles on its shaft, this means the inside shaft bearings have worn. This may cause a pulley misalignment. Awful bearings cause an audible growling sound. The external ends of the serpentine belt will fray and stretch out the belt. At some point the rubber belt grooves flatten out and trigger significant slippage. An excessively wobbling pulley can toss the belt off, leading to all the extras to quit functioning.
Lever Arm Freeplay
Some tensioner pulleys have markings on the housing that indicate the maximum selection 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 one position.
The tensioner pulley face must match to the other accessory pulleys with a parallel alignment. Placing an extended, straightedge ruler against the facial skin of the tensioner pulley, and flushing it against another item pulley, can gauge the angle. Any off-position measurement indicates worn shaft bearings in the pulley housing.
Serpentine Belt Noise
A moderately donned serpentine belt gives off a constant squeaking noises during engine idle. Belts which have worn severely task a loud chirping or squealing appear. The cause items to a glazed, put on or cracked belt. Dry or partially frozen tensioner pulley bearings could cause such sounds by wearing out the belt prematurely.
Lever Arm Oscillation
A lever arm that repeatedly oscillates backwards and forwards during idle or higher speeds means the the inside damper mechanism in the tensioner pulley has weakened or broken. This causes sporadic tension pressure on the belt and can manifest itself with intermittent chirping sounds.