Well, I broke another belt today.

This one was the most violent and the most destuctive.

Heres whats left of this one...



Now, i put a used one i had back on because after i put on a new belt and checked the crank pulley for damage, it did this in 200 miles!







Its kinda hard to see, but on the inboard side (closest to the block) there are a few deep grooves cut in.

On other belts, ive noticed a raised portion in the middle of the belt has been untouched, while both edges are worn down considerable.

Does this sound like am idler siezing up and letting go, or a bad idler bearing, or just a worn idler?

I'm at a loss. the pullies are clean, no debris, so thats what I, thinking.

 

This is funny, it seems like i am in the beginning stages of your problem, although i have yet to break another belt. I just checked my (2nd) gatorback recently (after about 400 miles of use) it felt like the backside of the belt began to get grooves in it...

What pulley combo are you using, and what size belt? Ive got 2%crank 15%sc and 5%altanator...and about 16k miles on the car....

 

19+3

and ive had almost 10k on this setup now

 

It looks like you have a misalignment of the pulleys. It doesn't take much to mangle a belt.

Rawhyde

 

I dont think its a pulley misalignment.

Ive gone 10k with these pullies on and they are all torqued properly, and they all had loctite on them when they were put on.

i think one of the tensioners is locking up at speed. amd burning off parts of the belt.

the grooves of the belt looks like brand new, but the top side, the only side that touches the tensioners, is beaten to hell.

oh well, looks like i need a new tensioner and idler....

 

Is there any way to measure/check pulley alignment? As far as I can eyeball it, my pullies seem perfect. Just wondering if there is a better way?

 

it sounds like slipping (loose) the inner portion is deflecting from centrifugal force like a tire would if under inflated.

 

Replaced my gatorback(1390mm) belt with the a stock size conti(1388mm). major difference in sound (quieter), i guess the gatorback was a tiny bit too long for my particular pulley combo(15%sc, 2%crank, 5%altanator)??????? Feel free to chime with with ideas here...

Had to clean the tensioner, it had a whole buncha belt particles all over it...

 

I threw on the stock crank and put on the stock belt and i had about 1/32nd of an inch clearence between the tensioner and the belt underneath is. now i see what happened and why it happened.

I went and got a 4060357 and i have about 3/4 of an inch clearance between the tensioner and the belt, so no need to worry about breaking or excessive wear anymore!

 

Good detective work

Glad you got it figured out!

Rawhyde

 

nice job!!!!