fan belts rolling over

[christopher]

why does this happen?
thanx
christopher
mci 5c

[Dreamscape]

Several reasons, misalignment of pulleys, differant or mismatched belts, incorrect tension or old stretched belts. What area are you having problems with?

Paul

[jlaney]

hello from  texas
i bought my prevost and found one of the belts was riding one groove off so i put it back in place and went on a trip to tulsa olk stoped and found it was one groove off again. this went on untill the belt came off while i was traveling . i had a full set of belts in the bay so i install a new one on the 871 engine . problem solved , i was the belt that was twisted. thanks jt.
tires have belts to slip and so do belts.

[Hartley]

If a belt is stretched or tightened too much it can start riding in the bottom of the pulley groove.

Now if by chance someone mis-measured for a new belt and went by the bottom of the V-groove instead of the outer edge, The belt could be too long.. This tends to build up stress inside the belt and it may vibrate or creep and flip over wearing the shape of the wedge away.. Then it may tend to roll over.

Many of these belts on Buses have to carry enormous loads. Wear patterns and cord separations can happen of they are not adjusted carefully and regularly. Dumping 30 to 50 hp through a single large V-belt is normal on a lot of MCI setups. It must be inspected and maintained, One flying loose could severely injure or kill a person if they happened to be standing there next to it.

My Riding Mower will roll a belt once in a while when it starts getting worn or stretched...
The problem is corrected by a new properly sized belt and the right tension setting.

Dave.....I have bought a few belts along the way.....DUH....

[HB of CJ]

Alsos sometimes the actual pullys are wrong for the application, usually you see this with rebuilt accessories like generators, alternators, power steering pumps, etc.. Seems the dimensions can be slightly different like from different countries of origin causing the belt to ride wrong like hi or low.

Do hope some engineer type bus person clarifies this point.  It apparently happened to me with my rebuilt replacement Victors VT-42 right hand power steering pump.  It had a wrong pully type on it--or soosss it was described to me by my trusty mechanic.  It was throwing belts until changed out.