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Originally Posted by quaddriver
well the average american drives appx 15K miles a year, making each change on average every 4 years, and, the average american trades in his car at appx 58K miles so if the impending large labor bill was one of the reasons why he traded the car, the next buyer has a nice surprise to add to his total.
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Why change the belt at 60k, when the mfr likely recommends 90k-120k miles, or 7 years (whichever comes sooner)?
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Originally Posted by quaddriver
My ears. An oiled chain buried inside the motor is far quieter than a kevlar reinforced rubber belt with cogs no less running on at least 2 pulleys behind a thin plastic cover.
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Well measurements don't support what your ears are telling you, except in very special circumstances (where someone went to a great deal of trouble to make a particularly quiet chain and a noise-attenuating cover to go over it).
some info on the subject:
http://www.hse.gov.uk/pubns/top10noise.pdf
"Noisy chain drives can often be replaced directly with quieter timing belts. Within the range of timing belts available, there are also quiet designs that use different tooth profiles to minimise noise. There is also a very new design of belt for applications where noise is critical which
uses a chevron tooth pattern to provide very quiet running. Noise reductions in the range of 6 - 20 dB are often possible using this approach."
http://www.me.ic.ac.uk/dynamics/stru...cona2000_2.pdf
"Even if timing belts are generally considered as silent transmissions, when compared to mechanical chains, nevertheless a large interest is devoted to further enhancement of the vibrational behaviour under operating conditions."
http://www.babcox.com/editorial/us/us70343.htm
"Play in a gear or chain style cam drive can cause noise, retarded valve timing and/or ignition timing depending on the engine design and application. With rubber timing belts, noise is seldom a problem even at high mileages. Valve timing and ignition timing (if it reads off the camshaft) also remain steady because timing belts don’t stretch."
http://www.powertransmission.com/fea...cdrivenews.htm
"The Browning HPT synchronous drive line from Emerson EPT combines the timing action of gears with the speed and noise level of belts. "