Belt mileage vs. condition

[01rangerxl]

Do you change belts based more on mileage or condition?

I have usually heard that serp belts should be changed every 60K miles or so. I changed the belt on my old truck at around that time. It had developed small cracks in the ribs, and in a couple places small pieces were missing from the ribs. My current truck had the belt replaced under warranty with the tensioner at 15K miles, so currently the belt has 70K miles and about 5 years on it. It looks like it was put on the truck yesterday. I can't see a single crack in the ribs or anything. Given its current condition, I think this belt will probably last at least another 30K miles or more. As long as I keep an eye on the condition, is this a good idea?

 

[The_Jeff]

Condition is your indicator. Lots of people are afraid of harmless cracks but you correctly ran it until chunks started falling off.

If you have an electric fan on the new truck vs belt driven on the old I see you getting much more life.

 

[pcfxer]

Looking at belts under tension is also an improper test. You should check a belt off of the pulleys, flip it inside out and sort of pinch it. If you see a lot of cracks, might as well change it now rather than end up at the side of the road. ;0.

 

[mechtech2]

I think the recommendation is 2 cracks per inch, then replace it.
The internal belt is pretty tough - rarely are there breaks or problems with that. It is the outside that can fail by deterioration.

 

[mechanicx]

Well I'd bet the belt would go another 30K with perodical inspections if it still looks that good now. but belts and hoses are funny how they'll give up without too much warning or signs of deteriation. Then you have an overheating vehicle with no alternator or power assist driving down the road. Sometimes when a belt goes they damage other things around them like the fan if it's a belt driven fan.

The OEM belts seem to be best and they are always the exact proper length not just "close enough", and worth what little extra they cost.

 

[SevenBizzos]

You change based on condition. Interior cracks of the belts are fine because that layer is the grip layer. When pieces start to fall off, changing the belt out is a good idea. When the cracks move into the second layer you should change. The outside layer has all the tension, so that should never show any damage.

 

[joel95ex]

new belts are not made the way they used to be, so they can appear to be in good condition when the heat may be weakening them. I would always inspect them visually but replace based on mileage...it is cheap insurance.....