Questions and Answers

Jeep Comanche Eats Drive Belts Q. I have recently acquired a 2WD 1988 Jeep Comanche. With only 63,000 miles it looks and drives well. The 4.0 liter motor has ample power and it promptly accelerates with impressive smoothness. There is only one plague I have encountered in my six months as the owner, I am on my third serpentine belt.

It went to a local shop at first, after it dumped a belt only a few weeks. Causation was attributed to a faulty water pump, which was replaced by the mechanics. About 6 weeks later it had ate that new belt for what seems no reason. It went back and they replaced it and gave particularly serious attention to the issue, and found nothing. They checked various things, among the suspected was the harmonic balancer or some other crankshaft slop~ they were found to be in good condition.

The belt was replaced and another 6 or 8 weeks later it had shredded it's third belt, I was directed to a Jeep Dealership and given repayment for my prior visit. Jeep replaced the belt and their mechanics could find nothing wrong either. They too had suspected a pulley problem or the harmonic balancer, but upon further inspection nothing was found. I was told to comeback in a few weeks for re-inspection.

I did and they thought the belt was wearing odd, slightly. The smooth outer portion of the first or second groove (toward the front) on the belt seems to be discolored (lost it's sheen), as if indicating it is being flexed or touched, though there is nothing apparent causing this. The two times the belt has shredded it has come off toward the front of the motor.

I can see as the motor operates that the belt has a very slight horizontal warble on every visible pulley, yet none of the pulleys seem to exude this as they spin compared to the fixed motor. The truck does not have A/C. As you can imagine I am now developing a belt phobia and am afraid to use the truck for camping ect. Do you have any ideas or experience which might illuminate this problem?

Thank you for your time,
John
Portland, Oregon

A. A timing light will come in handy here. When you hook it up you can use it to look at the pulleys while the engine is running and see which, if any are wobbling, misaligned or otherwise not right.