For decades, drive belts, V-belts, multi-vee-belts, and serpentine belts have been used to transmit power from the engine crankshaft pulley to accessories, 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 very well, or for lengthy, if at all, with incorrect tension. A loose drive belt won’t drive the item reliably, slipping and making noise. Car Pulley Belt Conversely, an excessively tight belt may cause item or pulley bearing damage. Various types of tensioner pulley preserve long-term engine and accessory quietness and reliability.
Tightening or Loosening
Sometimes, maintenance or repair will require tightening or loosening a tensioner pulley. Changing a drive belt or timing belt, for instance, would need you to loosen a tensioner pulley to make room for the new belt, as the new belt is smaller than the worn drive belt.
You’ll need to tighten a tensioner pulley, generally, after the installation of a fresh drive belt, or to change for a stretched drive belt that hasn’t worn enough to warrant replacement. Stretch belts don’t need tensioner pulleys but are “stretched” into place using a special tool-always use the special tool to prevent 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 an alternator, and NAI tensioners as adjustable idler pulleys. There are three types of tensioner pulleys and several ways to loosen them.
Mechanical tensioner pulleys are the simplest, many common, and least prone to failure. There is certainly one caveat, nevertheless, as mechanical tensioner pulleys need manual adjustment. This makes them prone to user error, leading to insufficient or extreme belt pressure. Additionally, they have to be adjusted to pay for belt stretch as time passes.