For decades, drive belts, V-belts, multi-vee-belts, and serpentine belts have already been used to transmit power from the engine crankshaft pulley to add-ons, like the power steering pump, air conditioning compressor, water pump, or cooling fans. Toothed timing belts and timing chains, too, are accustomed to transmit power from the crankshaft to the camshafts, plus some from the camshaft to camshaft, based on engine design.

The drive belt, timing belt, or timing chain won’t 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 preserve long-term engine and accessory quietness and reliability.

Tightening or Loosening
Sometimes, maintenance or restoration will demand tightening or loosening a tensioner pulley. Changing a drive belt or timing belt, for example, would require you to loosen a tensioner pulley to create room for the brand new belt, as the brand new belt is smaller compared to the worn drive belt.

You will have to tighten a tensioner pulley, in most cases, after the installation of a fresh drive belt, or even to change for a stretched drive belt that hasn’t worn enough to warrant replacement. Extend belts don’t need tensioner pulleys but are “stretched” into place utilizing a special tool-always use the special tool to avoid belt damage.

Tensioner pulleys generally fall into two types: accessory-integrated (AI) and non-accessory-integrated (NAI). Think of AI tensioners as adjustable accessories, such as for example 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 will be the simplest, the majority of common, and least susceptible to failure. There is definitely one caveat, however, as mechanical tensioner pulleys require manual adjustment. This makes them prone to user error, resulting in insufficient or excessive belt pressure. Additionally, they have to be adjusted to pay for belt stretch as time passes.