What causes V belts to twist?

Another common problem that people run into when checking their v-belts is called belt turn over.  There are a number of different reasons that belts can turn over in the pulleys. It can either be caused by a problem within the machine or improper installation by the operator.  

When trying to determine what is causing the belt to turn, start with the belt.  Most of the causes can be eliminated by replacing the belt with the manufacturers belt number and making 100% sure that the belt was installed correctly.  

The belt will need to not be pried on, the right belt type and cross section and the belt needs to be tensioned to the manufacturers specifications.  If you have a machine that has an automatic tensioner and you still have slack then you may have the wrong belt.

If you replace the belt and find the the belt is still turning over, move to the machine and see if there is a problem with the sheaves.  To see if the sheaves are misaligned your can either place the belt is the groove and see if there is a bend or, place a flat edge along the sidewall of the pulleys and make sure they are straight.