Operation and maintenance manual

QSB4.5 and QSB6.7 Drive Belts
Section 3 - Maintenance Procedures at Daily Interval Page 3-5
Cogged Belt
Inspect the belts daily. Replace the belts if they are
cracked, frayed, or have chunks of material missing.
Small cracks are acceptable.
Adjust the belts that have a glazed or shiny surface, which
indicates belt slippage. Correctly installed and tensioned
belts will show even pulley and belt wear. Refer to Section
A for belt adjustment and replacement procedures.
Belt damage can be caused by:
• Incorrect tension
• Incorrect size or length
• Pulley misalignment
• Incorrect installation
• Severe operating environment
• Oil or grease on the belts
Measure the belt tension in the center span of the pulleys.
Refer to the Belt Tension Chart in Section V for the
correct gauge and tension value for the belt width used.
An alternate method (deflection method) can be used to
check belt tension by applying 110 N [25 lbf] force
between the pulleys on v-belts. If the deflection is more
than one belt thickness per foot of pulley center distance,
the belt tension must be adjusted.
Refer to Section A for adjustment procedures.
For cogged belts, make sure that the belt tension gauge
is positioned so that the center tensioning leg is placed
directly over the high point (hump) of a cog. Other
positioning will result in incorrect measurement.