Serpentine belt

Passin Thru wrote:
Mine lasted 500,000 miles. If it gets cracks on the top side, change it. If it has cracks on the grooved side, unless there are chunks out of it, don't worry about it.

The old cracks and chunks criteria does not apply to the new serpentine belts. They wear out without appearing to be worn if you rely on a visual inspection only. There are wear gauges available to determine if a belt is worn. As stated in my previous post, I was relying on the visual inspection I did prior to that trip. An after the fact inspection using the appropriate tools verified the belt had worn and was no longer making proper contact with the pulley groves. (If you question what I said, do some research to verify it for yourself.)

Thank you to all the responders.
I think I will change it and keep the original for a spare in case.

Mine lasted 500,000 miles. If it gets cracks on the top side, change it. If it has cracks on the grooved side, unless there are chunks out of it, don't worry about it.

Mine failed at approximately 70,000 mies and eight years. It looked good via visual inspection prior to leaving on the trip which ironically included a stop at Freightliner in Gaffney, SC for some preventive maintenance work. The serpentine belt replacement was one of the items planned to be taken care of - it failed about 800 miles short of Gaffney.

It all depends! You change the serpentine when it starts getting cracks on the rubber inside the belt. I had my coach in for service at Freight liner in Las Vegas and I have 60K miles on my coach. But I have had it since 2003. The mechanic insisted that the belt did not need changing out. So I just bought the two belts and carry them in a compartment. Next service I will tell them to check it again and if it needs it, I have the belts. It it breaks while on the road, then I call Coach-Net.

Ivylog wrote:
It's probably good for ten years BUT do you want to change it on a hot engine on the side of the road without a diagram of how it goes on?

X2

We had ours replaced on our previous coach at 6 yrs. old and 50,000 miles (8.9 Cummins 425 ISL). The belt was showing cracks on the underside (top looked good).

MM.

I'd go ahead and replace it for the reason Ivylog stated, especially if you can do it yourself. I just replaced the belt on my daily driver at 7 years 160k miles. The old belt showed no signs of wear or cracking.

It's probably good for ten years BUT do you want to change it on a hot engine on the side of the road without a diagram of how it goes on?

BigSkyBob wrote:
Replaced mine after 7+ years, just cause. Still looked new and was fine as per my wear gauge. Kept it as a spare.

That's the way I done it and now have a spare that I know will fit.
For the OP, most quality belts will deteriorate from age before they wear out with mileage.