Timing Belts? A timing belt is a small but crucial engine part that can keep a
motor running properly and improve fuel efficiency. While not all engines have
belts, they are the most common over timing chains or timing gears. The belt
wraps around a series of gears at the front of the engine to aid in “timing” the
opening and closing of fuel valves. Made from the same material as most other
engine belts, they are not the most durable part and will wear out eventually.
Timing belts are normally used in smaller engines, but only rarely in larger
ones. Timing belts are relatively new additions to the modern automobile, being
only sporadically utilized as early as 1945. The first practical mass-market use
was in 1962 when a timing belt was successfully incorporated into the German
built Glas 1004. This was followed in 1966 by that year’s Pontiac Tempest
automobile and soon became the template for the future use in all commercial
vehicles to follow. Function the function of a timing belt is to turn the
camshafts at exactly one-half the speed of the crankshaft. The camshaft manages
the opening and closing of the intake and exhaust valves with the up-and-down
movement of the pistons in the cylinders. The valves must open and close at the
proper rate, so the timing belt must be calibrated properly to move the valves
in time with the correct motion of the pistons. The camshaft and crankshaft gear
both have a timing mark on them that must be aligned correctly prior to putting
the timing belt on the gear teeth or the engine will not run. It’s is important
to change the timing belt at recommended intervals. If you’re unsure when to
replace it, the vehicles owner’s manual, manufacturer, or dealer can offer this
information. This will range from every 60,000 to 105,000 miles. It is best,
though, to not let a belt go more than 80,000 miles even if the belt is rated
The lack of a timing belt makes any equipped vehicle nothing more than a
stationary hunk of metal. Proper understanding, installation and maintenance of
this important part will keep any engine running perfectly for years. Timing
belt replacement intervals are important but you should always have your
vehicle’s timing belt checked periodically as oil leaks from the camshaft and
front crankshaft seals cause the life of the timing belt to be greatly
Most of today’s timing belt driven vehicles are interference engines.
To put the definition of a interference engine into simple terms is this, if
you timing belt breaks or slips you will MOST likely have
severe engine damage.
The interference type engine may experience serious
damage when the timing belt breaks. This is because the cylinder valves stop
moving while the pistons continue on a collision course. This potential for
engine damage underlines the importance of servicing this key engine component
before it fails. After time and mileage the teeth on the belt weaken and may
break off without notice. When this happens the cam timing changes, usually
radically, causing the engine to stop running.
The advantages; Intake and exhaust valve timing durations are longer and the
lift is also increased. This allows more “fresh air/fuel” in and more exhaust
out per cycle. The disadvantage is the piston and valve can “Kiss” if the timing
belt breaks. The good thing, with normal maintenance and following manufacturer
recommendations for changing the timing belt very few belts just break. If they
do, it is very rare. Usually it is because the engine gets over revved, oil
leaks from the cam seals on the belt, seized water pump or a bad idler pulley.
If you have an interference engine change the timing belt when you should and
you will be fine.
The non-interference type engine does not experience
damage when the timing belt fails. Even so, the inconvenience and expense of an
unexpected vehicle breakdown are avoidable by servicing the timing belt on
Does your vehicle have an interference engine???
Today!!! ( 734) 327 6488