Doubting the manufacturer
Question : THE owner's manual of my 1997
Toyota Corolla specifies the timing
belt change interval as 100,000km.
This seems to be rather long and I
am worried that the belt may snap
before the recommended mileage is
Should I stick to the manufacturer's intervals or would it be better
to have the belt renewed at shorter
VEHICLE manufacturers test renewable
parts, such as timing belts, extensively
during the design and engineering
stages of vehicle development and the
engineers would have included an
allowance or margin of safety in specifying the renewal interval.
For example, they may recommend a
replacement interval of 100,000km for
a component that fails at 120,000km to
150,000km during evaluation.
If this recommendation were to be
revised at a later stage, you would be
informed either by post or when you
bring the vehicle in for servicing
(another advantage of using an authorised service dealer).
If you are still in any doubt, or simply for peace of mind,
you could reduce the change intervals by approximately 15% to
20% This means changing the belt at around 80,000km to 85,000km
intervals instead of 100,000km.
Always renew the timing belt along
with the belt tensioner since failure of
the latter would inevitable result in
the destruction of the belt and, ultimately, the engine.