For decades, drive belts, V-belts, multi-vee-belts, and serpentine belts have been used to transmit power from the engine crankshaft pulley to components, such as the power steering pump, air-con compressor, water pump, or cooling fans. Toothed timing belts and timing chains, too, are accustomed to transmit power from the crankshaft to the camshafts, and some from the camshaft to camshaft, depending on engine design.

The drive belt, timing belt, or timing chain will not work well, or for very long, if, with incorrect tension. A loose drive belt won’t drive the item reliably, slipping and making sound. Conversely, an excessively tight belt may cause item or pulley bearing damage. Various kinds of tensioner pulley keep long-term engine and accessory quietness and reliability.

Tightening or Loosening
Sometimes, maintenance or restoration will demand tightening or Car Pulley Belt loosening a tensioner pulley. Replacing a drive belt or timing belt, for example, would need you to loosen a tensioner pulley to make room for the new belt, as the brand new belt is smaller compared to the worn drive belt.

You will have to tighten a tensioner pulley, generally, after the installing a fresh drive belt, or to modify for a stretched drive belt that hasn’t worn enough to warrant replacement. Extend belts don’t require tensioner pulleys but are “stretched” into place using a special tool-always utilize the special tool to avoid belt damage.

Tensioner pulleys generally fall into two types: accessory-integrated (AI) and non-accessory-integrated (NAI). Think about AI tensioners as adjustable components, such as an alternator, and NAI tensioners as adjustable idler pulleys. There are three types of tensioner pulleys and several methods to loosen them.
Mechanical tensioner pulleys are the simplest, the majority of common, and least prone to failure. There is usually one caveat, however, as mechanical tensioner pulleys need manual adjustment. This makes them prone to user error, leading to insufficient or excessive belt pressure. Additionally, they have to be adjusted to pay for belt stretch over time.