98 Sport 4.0 SOHC eats 2 serpentine belts in 2 days, what's up?

[Pro Mod]

My belt broke yesterday, and I was expecting it. It had looked rough, and I actually had a new one in the trunk; I just hadn't had time to replace it. So I install the new one on the side of the road and go 8 miles home.

So today I drove about 10 miles from home, and the new belt broke about 5 miles from home on the return trip. Obviously there's a problem somewhere. The belt was installed 100% accurately yesterday. The idler pulley seems to be just fine, but everything was a bit too hot to see if the pulley on the tensioner is locked up.

How common is it for the belt tensioner to take a dump on the 4.0 SOHC's, therefore eating belts? Truck has 159,500 relatively trouble free miles btw.

As of right now the truck is about 1/2 a mile from home. After it initially cooled off I drove it as far as I could before it started getting too hot for my taste (since I was pretty close to home). I'm at home waiting for it to cool off again so I can bring it home for a good look over.

 

[koda2000]

you've probably got a bearing locking up when it gets hot. this will cause the belt to snap or burn through. look for a small pile of burnt rubber. did the belt shred or break clean across?

 

[Pro Mod]

Shredded. Absolutely.

 

[koda2000]

Shredded. Absolutely.

shredding is usually a sign of pulley misalignment and don't forget to check the harmonic balancer/crank pulley too. they can come apart.

 

[Pro Mod]

As I suspected, the belt tensioner was junk. Not only were the bearings in the pulley shot, but the housing was starting to separate as well. I imagine this was causing the pulley misalignment, shredding the belt.

Luckily my local Advance Auto had a new tensioner in stock on a Sunday, and I installed the new tensioner and belt in time to watch the start of the NASCAR race!

Thanks for the help.

 

[SoNic67]

Didn't make noise before? Squeal?

I never leave something like that to break first and then repair it, because I am not that lucky - it usually breaks far from home.

 

[Pro Mod]

Yeah it never made a peep. Im totally **** about strange noises, to the point that my wife thinks I'm obsessive lol. It never made any strange noises at all. I consider myself lucky I was close to home.

The belt had been looking slightly rough, but not that bad and I was just attributing it to mileage. Just normal "wear" until this episode.