Belt tensioner 02/910462 JCB JS, aftermarket

Belt tensioner 02/910462 is an aftermarket part for the JCB JS205 excavator. The card also lists 3937553, 3914086, 6731-62-4110.

The automatic tensioner keeps the multi-rib belt tight with spring force so that the alternator, water pump and fan turn without slipping. A weak spring lets the belt squeal and slip, charging drops and the engine can overheat; a worn pulley bearing shows as a hum and uneven belt wear. The pulley bearing is sealed and needs no greasing. The belt is driven from the crank pulley, and the tensioner works on its slack side. The tensioner comes with its spring preload set at the factory and needs no adjustment. The tensioner is replaced as a complete unit.

Specifications

Compatibility

The tensioner with Cummins number 3937553 is used on excavators with Cummins engines. Other parts are in JCB Dieselmax engine.

Fitting

When fitting the new tensioner, inspect the belt for wear and cracks and replace it if needed. Tighten the bolts evenly and check with the engine running that the belt runs without flutter. Replacing the belt together with the tensioner lets both serve the same length of time.