Timing belt

[beater]

I just rebuilt my 1800 in my 1977 Spider and it is running great. Of course I replaced the timing belt but since these are interference engines I am always paranoid about belt breakage. Is this a common fault and are there some belts that are more prone to problems than others?

[131]

Is this a common fault and are there some belts that are more prone to problems than others?

If you use a good brand belt and change it as often as Fiat recommended than it's not an issue.

[RRoller123]

This raises an interesting survey question: Has anyone here ever had a timing belt break that had less than 30,000 miles on it? I haven't read here of any instances of this happening yet.

[maytag]

funny, we just had a similar thread on another forum I'm a member of for a different brand of Italian car.

In that forum, the recommended belt-service interval is under 10k miles for most models. This seems excessive, when weighed against other cars with rubber timing belts. And with those cars, most models (including my own) require removing the engine for this procedure. And so the question was raised "has anyone ever had a belt break, and how many miles were on it when it did?"

There were not enough instances of belt failure to see a pattern in their age, or their climate, or their models. But what WAS clear was the catastrophic nature of damage to those motors due to a broken belt.

Transpose that information to our cars: I don;t know why replacing the timing belt shouldn't be added to all of our seasonal maintenance. Do it annually, in the spring when you bring it out to begin driving it. You're already replacing oil, filters, etc etc. Might as well add this $35 belt to that list. Because a belt failure will inevitably result in opening the motor.

[Dawgme85]

I've heard of one instance, where a local Fiat mechanic decided to see how long a timing belt would last in his own car and ended up changing it at 55 or 60k miles because he was so nervous that it might "go" at any time. This was relayed to me by his wife.

As they say, YMMV

[azruss]

I commonly replaced belts at 50-60k miles without anyone of them looking close to failing. Now that i'm in arizona, i probably will change it like i would tires.

[bradartigue]

I just rebuilt my 1800 in my 1977 Spider and it is running great. Of course I replaced the timing belt but since these are interference engines I am always paranoid about belt breakage. Is this a common fault and are there some belts that are more prone to problems than others?

I have never had a belt fail on a twin cam. Not the pirelli belts, not the FIAT belts (which were pirelli), not the cheapest junk belts. I've pulled cars out of fields that have sat for years with 90k on the belts and never had them fail, and I've run them with cloth hanging out of the sides of the belts.

Now I wouldn't recommend any of this; get the best belt (pirelli) you can, install it, and drive it. In 5 years change it.

[djape1977]

i've driven up to 100.000 kms (that would be 60-70k miles?) in 10 years without changing timing belts.
never had a failure.
if the car sat for a long time, like 5 or more years without engine being turned over regularly, i first replace timing belt, just to be safe.
if it's installed properly, i don't see how it could "jump" or why it would break.
most common reason for failure is undertightened tensioner.
when installing a T-belt, allign everything, tighten the tensioner, turn the engine by hand at least 3-4 full cycles, than re-tighten. there should be almost no slack in t-belt, 4-5mm at most on drivers side



i've seen t-belt strip it's teeth after 15k miles or so twice, on two types of modern cars, and both times it turned out to be chinese copy of "gates" brand. on their website there's extensive explanation how to recognize fakes, but any half decent mechanic should be able to tell it ain't good by just feeling it. it feels more like plastic than rubber.
we seem to be safe since i don't think chinese would bother making a copy of a t-belt that's not sold so often.