MAINTENANCE, LUBRICATION AND SERVICE
DRIVE BELT REPLACEMENT INTERVALS
Check pulleys for debris, clean as
needed.
Rib Cracking
An in-service poly V-belt will go through
several phases of cracking during its life.
After an extended time in service, minor
rib cracks may appear, usually one or
two cracks per inch. This cracking is
normal.
Belt With Minor Cracking
Belts should not be replaced unless the
ribs exhibit severe multiple cracking as
shown below. Multiple cracking will lead
to rib chunking.
Belt With Multiple Cracking
Belt With Severe Cracking
Rib Sidewall Glazing
When the belt ribs appear to have a
shiny surface that is hard and brittle, it is
usually an indication of belt slippage.
This is attributed to inadequate tension
and/or extreme temperature. Both these
conditions will lead to severe cracking
and belt failure, often with little advance
warning. If this occurs, locate the cause
and correct before installing a new belt.
Belt Wear
Accelerated wear on any part of the belt
(fabric backing, tensile cord or rib
rubber) is a concern and should be
investigated for cause, and corrected
before installing a new belt.
Possible Causes of Accelerated
Belt Wear
• Drive belt performance will be
adversely affected when misalignment
exceeds 1/16 inch for every 12 inches of
belt span.
• Belt length must be correct.
• Environmental conditions,
temperature, exposure to engine uids,
etc.
• Abrasive materials, small stones, metal
shavings, etc.
Foreign Objects
Any object protruding in the path of the
belt drive and contacting the belt will
cause damage and eventual failure.
Locate the object before installing a new
belt.
Noise, Vibration and Harshness
(NVH)
Poly V-belt drive systems were designed
to prevent Noise, Vibration and
Harshness (NVH) problems. Field
problems, however, which may be
related to NVH causes occasionally
occur.
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X Publication_PC28
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