Why do California timing belts last longer ?

Well Ken,
I think for the most part, you ae correct. The BIGGER problem is the
belt tentioners. At 120,000 miles, you will "need" to change them ! If
you can spin them (with the belt off), they are shot! Last year, I saw a
'97 that the tentioners had failed and came out thru the front cover and
into the radiator. Damage to the engine it's self, was only replaceable
plastic parts. Damage to the fan and radiator was total ! Many
tentioners are gone long before 100,000 miles and just waiting to fail.

Bruce RED '91

On Fri, 15 Oct 2004 21:29:47 -0700, (BRUCE HASKIN)
wrote:

>Well Ken,
>I think for the most part, you ae correct. The BIGGER problem is the
>belt tentioners. At 120,000 miles, you will "need" to change them ! If
>you can spin them (with the belt off), they are shot! Last year, I saw a
>'97 that the tentioners had failed and came out thru the front cover and
>into the radiator. Damage to the engine it's self, was only replaceable
>plastic parts. Damage to the fan and radiator was total ! Many
>tentioners are gone long before 100,000 miles and just waiting to fail.
>
> Bruce RED '91
>
If you can "spin" the tensioner, then there is no grease left in the
bearing and indeed it will soon fail. It is possible on many
tensioners (I haven't done a Miata yet) to pry carefully around the
edges of the seal and then clean and repack the bearing. With fresh
high quality grease the tensioner will last a long time.

I don't think that is the answer. If you hold the tentioner in your hand
by the center, you will find that you can wiggle the "main" outside
part. That means the bearing is warn out. (and the bearing is ready to
fail) The one that came out of my '91 at 120,000, was clean and no real
sign of lub on the outside of the bearing. As long as you have the belt
assembly. apart, you should just replace the tentioners. "And the water
pump !" (it's cheap insurance)

Bruce RED '91