The auxiliary belt drives the alternator, the water pump on many engines, the power steering pump and the other units on the front of the engine. Its tension is held by a tensioner: a spring-loaded arm with a pulley on a bearing, often with a damper inside that stops the arm bouncing, and one or more idler pulleys that guide the belt around the drive. On engines with a timing belt, a tensioner of the same kind holds the timing belt against its sprockets.
Tensioners fail in the bearing and in the arm. The bearing loses its grease with heat and age, whines, then grinds and can seize or let the pulley wobble; the spring loses its force or the damper leaks, the arm bounces and the belt flutters, squeals and slips, so the alternator undercharges and the water pump slows. A belt that comes off or breaks stops the water pump and the alternator at once. On a timing belt drive, a failed tensioner lets the belt jump a tooth or break, and the pistons strike the open valves.
MONTTRON tensioner bearings are made to OEM-compliant quality and as aftermarket spare parts: the pulley diameter and profile, the bearing, the arm geometry and the spring or damper of the original, so the tensioner fits the original bracket and runs the original belt at the original tension. The materials are tested for durability and temperature resistance.
The range covers European and Japanese passenger cars. Each reference is identified by the OE number of the original part; send that number and the vehicle identification number (VIN) and we confirm the matching MONTTRON reference.
For availability and OE cross-references, contact us by email.