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The base holds the other parts, and the spring keeps the belt pulled tight. The pulley is what facilitates movement of the belt. The tensioner arm is found on the bottom of the tensioner, and if you press on it, it will work against the spring, delivering enough slack so that you can adjust or remove the belt.
How does a tensioner work?
A tensioner is a device that applies a force to create or maintain tension. The force may be applied parallel to, as in the case of a hydraulic bolt tensioner, or perpendicular to, as in the case of a spring-loaded bicycle chain tensioner, the tension it creates.
How does an auto belt tensioner work?
The automatic belt tensioner is a spring-loaded idler pulley that maintains constant tension on the drive belt at all engine speeds. The faster that the engine turns, the belt gets stretched more which actually makes the belt loose.
What are the symptoms of a bad belt tensioner?
Rust bleed and cracks. Appearance: Rust is bleeding between arm and base or dripping from the tensioner. Pulley bearing wear. Pulley wear. Tensioner assembly misalignment. Tensioner noise. Tensioner arm misalignment. Excessive tensioner arm oscillation. Binding or grinding tensioner arm movement.
Can a belt tensioner be adjusted?
Cars equipped with an automatic belt tensioner adjust themselves over time and do not require adjustment. This article shows you the process to adjust drive belts on a pivot-style belt adjuster.
Are all belt tensioners the same?
There are three main types of belt tensioners found in the replacement auto parts market. Each one works a little differently, but all ensure that your alternator and auxiliary pumps receive the power needed to keep your car or truck moving.
Does a belt tensioner spin?
Checking the Tensioner Spin the pulley to see if it spins freely. If you hear grinding or the pulley doesn’t spin freely, replace the tensioner. When you replace the belt, it should take a lot of muscle power to move the tensioner. If you can move it easily, the spring tension is most likely not tight enough.
Is it safe to drive with a bad belt tensioner?
Driving with a bad belt tensioner is unsafe since the tensioner is meant to guarantee ample tension that powers accessories. Wear on the belt tensioner will eventually cause the belt to slip, generate loud noise, and also create an unsafe level of heat along the accessory pulleys.
Should a belt tensioner wobble?
A wobbling belt tensioner can result from many different causes. In general, belt tensioners tend to get noisy when they fail. You can even remove the belt, spin each pulley, and listen for rumbling or other noises. If the belt tensioner is moving more than it should, there is a good chance it will require replacement.
What does a bad tensioner sound like?
Symptom 1: Squealing, rattling, or chirping. When the tensioner or tensioner pulley fails, the loss of tension can cause the belt and pulleys to make high-pitched rattling or chirping noises. If the pulley bearing completely fails, it can also cause a squealing or even a grinding noise.
What will a bad belt tensioner do?
Another symptom of bad or failing drive belt tensioner is failure of the belt driven accessories. A seized or loose drive belt tensioner can cause the belt to snap, which will disables those accessories and can cause problems such as overheating, a dead electrical system and battery, or a disabled AC system.
What causes tensioner to fail?
A seized tensioner cannot maintain proper belt tension. Dirt or mud can also jam the tensioner housing. A loose or worn pivot arm can allow unwanted movement; that results in belt noise and misalignment. Over time, this will increase belt wear and lead to premature belt failure.
How do you align a tensioner pulley?
The accessory belt needs to be loosened before the adjustment bolt can be turned on the side, top or bottom of the pulley. Turn the adjustment bolt clockwise to tighten the pulley.
Can a tensioner pulley leak oil?
The hydraulic oil that maintains this tension can seep out of the tensioner. When it does the associated engine belts become loose. A car that leaks oil is not an uncommon sight. This is often due to a loose timing belt, which arises due to leaking from the tensioner.
How do I know if my tensioner pulley bearing is bad?
Listen for a fluttering” noise while driving or while the car is idling. This indicates the tensioner is too loose. Other noises such as squealing or whirling from the front of the engine mean the spring inside the tensioner is weakening. In this case, the belt tensioner needs to be replaced.
What happens if the tensioner pulley fails?
When the tensioner or tensioner pulley fails, the loss of tension can cause the belt and pulleys to make high-pitched rattling or chirping noises. If the pulley bearing completely fails, it can also cause a squealing or even a grinding noise. Symptom 2: Knocking or slapping. This can cause a slapping or knocking noise.
Can a bad belt tensioner cause misfire?
The belt may oscillate between too little tension and too much tension. The belt will slip and catch, causing noise and vibration. This can cause a change in crankshaft speed that can be severe enough to cause the engine management system to think that a misfire just occurred.
Why do V belts fail?
Missing cogs can cause belts to slip and fail, when it is discovered there are teeth missing, the belt should be changed immediately. The most common reasons your belt could be missing a cog are excessive heat, the pulleys are too small or misaligned. It can also be caused by improper or prolonged storage of belts.
How long do belt tensioners last?
Most modern cars that roll off the dealer’s lot as a new vehicle will have a 60,000 to 100,000-mile life expectancy for the serpentine belt, tensioners, and idler pulleys.
Should I replace idler pulley and tensioner?
If there is any wobble, squeak, or undue friction, the idler pulley should be replaced. The best way to maximize the idler pulley’s lifespan is to maintain proper tension on the serpentine belt and replace belts with new ones whenever required.
