The majority of modern day engines employ timing belts as a means of power transmission between crankshaft and camshaft etc.
If fitted correctly and changed at the mileages recommended by the vehicle manufacturer, then there is no reason why a timing belt cannot be a reliable part of the engine unit.

All of European original equipment and aftermarket belts are produced by four main manufacturers. These are "Continental", "Dayco", "Gates" and "Goodyear". Accordingly there is no such thing as a cheap belt as even the aftermarket own brand belts are manufactured by these four reputable international companies.

A timing belt is constructed of a multi-core of extremely strong fibreglass, or Kevlar cords around which is moulded high temperature neoprene rubber. The teeth formations are further covered in an elastic nylon facing which promotes excellent wear resistance with low friction properties.

Timing belts are unlikely to fail due to faulty manufacture and unfortunately most failures are the direct result of hostile operating conditions and/or unprofessional fitment. Failed belts always exhibit visual features which can identify the cause of failure.

The following pages are dedicated to the common features exhibited by failed timing belts and explanations are given for their causes. In some instances several of these features may be witnessed on one belt failure possibly due to a multi-fault operation. For your information remedial actions are suggested.