How to Guide
BELT FAILURE & REPAIR GUIDE
Problem Cause Remedy
Belt breaking after tting Forcing the belt over the pulley when tting, damaging the cord and cover Reduce drive center distance to t belt
Contact with foreign objects, ex: a stone while operating Fit an effective guard
Cuts and splints in the base of the belt Outside idler pulley in use Replace with inside idler pulley on the slack side of the drive. Increase the
size of the existing idler pulley
Pulley diameter too small Redesign using recommended minimum pulley pitch diameters
Ambient temperature too high (above 158° F / 70° C) Ensure good ventilation and protect belts from direct heat
Ambient temperature too low (below -40° F / -40° C) Warm area surrounding drive
Contamination by oil or chemicals Protect drive from contamination
Abnormal belt slip Check the drive design to ensure correct number of belts, redesign if
necessary. Check the drive tension.
Severe belt vibration Drive has insufcient belts Check drive design and modify if necessary
Center distance longer than recommended Shorten centers, use an inside idler in the drive slack side
High shock loading Use an inside idler in the slack side
Belt tension too low Correct belt tension
Unbalanced pulleys Balance pulleys
Belts turn in pulleys Poor drive alignment Realign pulleys
Excessive belt ap Use an inside idler in the slack side
Belt tension too low Correct belt tension
Worn out belt Replace belt
Excessive wear on belt anks Incorrect pulley groove angle Replace with correct pulley groove angle
Excessive wear in grooves Replace pulleys
Drive misalignment Realign
Pulley diameter too small Redesign using recommended minimum pulley pitch diameters
Belt swelling or softening Contamination by oil or chemicals Protect drive from contamination
Unusual belt stretch Worn or wrongly machined pulley grooves Replace pulleys
Used belts mixed with new belts on the drive Replace with a new set of belts