== == it is a free pulley that works as a tensioner on any belt bolted to hold or spring loaded
An idler pulley usually tensions a belt.. eg supercharger belt is kept taut by its respective idler pulley
Idler pulleys are used to maximize belt contact with other pulleys and to redirect belt around other parts that might interfere with the belt.
They very in price, depending on the car, from around $12 to $80.
there is one, but two if you count your belt tensoiner.
only if the idler arm will not hold the tension on the belt and the pulley needs replaced when the are warn sharp or warn flat
A deflection pulley is used to change the direction of a belt or chain, while an idler pulley is used to maintain tension in the belt or chain. In other words, deflection pulleys guide the belt around corners or obstacles, while idler pulleys help keep the belt taut and prevent slipping.
The engine usually has an idler and/or tensioning pulley as well as a few pulleys that use the power of a traveling serpentine belt to drive components such as the alternator, a/c pump, etc. Any of the pulleys that have one or more grooves that assist to guide the belt(s) are, technically, sheaves. Idler or tensioner pulleys that are completely flat because the flat back of the belt rides on them are not sheaves, but are pulleys.
Take it to the dealer! It's not a job for the timid or any shop that doesn't know what they are doing. Make sure you get the idler pulleys and automatic tensioner replace along with the timing belt. If the bearings seize in those idler pulleys it will ruin the belt and in turn take out your engine.
The 2001 Ford F-250 with a 7.3-liter diesel engine typically has two idler pulleys. These pulleys are part of the serpentine belt system, which helps drive various engine accessories. It's always a good idea to consult the vehicle's service manual or a parts supplier for the most accurate information specific to your truck's configuration.
take pressure off the belt by pulling back the spring tensioner. Remove old belt, put the new belt on all the pulleys but the idler pulley, pull the tensioner back slip belt on to idler, Look to make sure you have the belt on all pulleys good, your done.
Worn or incorrect belt. Defective, glazed idler or pulleys.
In automotive terms, There are drive pulleys such as the drive pulley mounted to the crankshaft on most engines. There are driven pulleys such as an alternator, power steering, water pump, a/c compressor and all the accessories driven by the drive pulley. There are idler pulleys and tensioner pulleys. There are timing belt pulleys. And for non automotive related terms, There are block and tackle pulley systems. There are pulley hoists. Wire rope pulley blocks. Cable pulleys. Rope pulleys.
Use a "straight edge" to make sure that the "valley" area (where the belt rides) is in alignment with the other pulleys