Throwing belts

[shadango]

On my way home from a cruise this evening I got a little....ahem.....spirited in my driving and dropped into first at about 40 mph and revved high to pass....pulled hard and great......but then started smelling burning rubber....and it wasnt from my tires....

Soon I felt the steering wheel get heavy and the lights went dim.....saw the temp gauge creeping up......

I knew then I threw a belt.....well, was close enough to home to nurse it back....

turns out I threw both belts.    My guess is the alt belt thre first and then snagged the water pump/power steering belt.......nothing bent or damaged but the belts both had cuts in them.

I have seen this happen to someone before......so I know it happens....

I guess the only way to prevent this from happening would be to convert to serpentine?

I did notice that I have a bit of a whiney sound now with the new belts on.....like a whistling sound...not real loud...but there.....not sure if its the new belts seating or what ...everything looks good under the hood now.....

How tight do you guys make your belts?

[72cudamaan]

I am thinking 1/2 to 3/4 inch deflection is good.

[PlumCraZRT]

You sure your pulleys are lined up?

[Chryco Psycho]

bent or misaligned pulleys is the usual cause , on my Duster shifting at 7200 i had to run a belt tensioner on the outside of the belt , I could find no other way to keep it on

[mr_340]

check your crank pulley. had that happen to me on the way out to Woodward this year. turns out the crank pulley was cracking at the mounting surface, all bolt were still tight but the cracking allowed the ps pulley to wobble and throw the belt.

[72cudamaan]

Question #1  Have you thrown the belt(s) before?
Question #2  Could it be possible that the sudden change in rpm's
put a little slack in the belt and made it come off?  An anomoly of sorts if you may.

[shadango]

Question #1  Have you thrown the belt(s) before?
Question #2  Could it be possible that the sudden change in rpm's
put a little slack in the belt and made it come off?  An anomoly of sorts if you may.

Never did it before....that is my guess (hope) too.....just the sudden huge jump in RPMs.....

[mr_340]

Never did it before....that is my guess (hope) too.....just the sudden huge jump in RPMs.....

If its something new take it out and beat on it again and if it happens again,  look carefully at your crank pulley.
Are you running original pulleys, resto's aka Buchilon or Aftermarket( March)??

[tman]

Mr340, nice pic of that pulley.  I have heard of this condition, but have never seen it till now.  Thanks for show'n.

[shadango]

If its something new take it out and beat on it again and if it happens again,  look carefully at your crank pulley.
Are you running original pulleys, resto's aka Buchilon or Aftermarket( March)??

From what I can tell, just original type pulleys....in good shape though last I checked (when I put everything together in april of 2009)

Will flog her again and wait and see what happens......it could have been that the one belt in the back (alt) got loose and caused the other to kick off.......I guess this is one of those "time will tell" things......I aint all that patient....LOL

[BS CUDA]

Careful - I was throwing stock belts and went March serpentine but would still occassionally shred the power steering belt - alignment looked good? Then out of the burnout box came bouncing the crank pulley - sheared 5 of 6 bolts. Seems the power steer belt slipped and tied itself somehow - drove back on the trailer tho . Anyhow once new pulley, rad, fan and belts were installed had it laser aligned and found the power steer pulley wuz tipped slightly but was hard to notice by eye. No problem since - knock on wood / fingers crossed.

[HP2]

Serpentine isn't the only way to avoid this. Like others have said, check your pulleys to make sure they are intact and not cracking or bent. Also inspect for dents and dings. Concentricity or run out should be eyeballed as well. If a pulley is out of round, that doesn't help the belt retention situation. Alignment is critical and needs to be viewed in two seperate planes, not just from above, but also from the side. A slight angle on one component can create similar alignment problems. Another often overlooked condition is the width of the belt in relationship to the pulley. Sure big thick belts can take a lot of tension, but a thinner belt with less tension that fits lower in the groove will resist throwing better than a thicker belt that sits high in the groove.

[shadango]

Serpentine isn't the only way to avoid this. Like others have said, check your pulleys to make sure they are intact and not cracking or bent. Also inspect for dents and dings. Concentricity or run out should be eyeballed as well. If a pulley is out of round, that doesn't help the belt retention situation. Alignment is critical and needs to be viewed in two seperate planes, not just from above, but also from the side. A slight angle on one component can create similar alignment problems. Another often overlooked condition is the width of the belt in relationship to the pulley. Sure big thick belts can take a lot of tension, but a thinner belt with less tension that fits lower in the groove will resist throwing better than a thicker belt that sits high in the groove.

On my one pulley the belt does sit higher..........how do you find a beltt hat is thinner but still the same size as far as fitting the pulleys?  I thought it was pretty much whatever the manufacturers made you are stuck with???

[HP2]

Gotta have a friend at the parts counter willing to work with you on it. Take you belt in, tell them you want an identical length in a thinner profile. Years ago this was an easy task as everything ran V belts. These days its a bit more challenging because of the proliferation of seprentine, but still not impossible.

There also is the ever resourceful Mcmaster-Carr website; http://www.mcmaster.com/#v-belts/=f38umu