Operation and maintenance manual

QSB4.5 and QSB6.7 Drive Belt, Cooling Fan
Section A - Adjustment, Repair, and Replacement Page A-15
CAUTION
Applying excessive force in the opposite direction of
windup or after the tensioner has been wound up to
the positive stop can cause the tensioner arm to
break.
NOTE: Make a diagram of the belt arrangement prior to
removing the drive belt. This aids in installation and
proper routing of the cooling fan drive belt.
NOTE: The location of the belt tensioner can vary,
depending on the front engine accessory arrangement.
Pivot the tensioner in the direction of the spring tang to
remove the belt.
Remove the belt.
Clean and Inspect for Reuse
Inspect the drive belt for damage.
Transverse (across the belt) cracks are acceptable.
Longitudinal (direction of belt ribs) cracks that intersect
with transverse cracks are not acceptable.
If the belt is frayed, punctured, or material is missing, the
belt is unacceptable for reuse and must be replaced.
Inspect the belt grooves for:
• Embedded debris
• Uneven/excessive rib wear
• Exposed belt cords.
Inspect the backside of the belt for:
• Glazing (high heat)
• Embedded debris
• Exposed belt cords.
If any of the above conditions are present, the belt is
unacceptable for reuse and must be replaced.
Inspect the idler and drive pulleys for wear or cracks.
Plastic pulleys often have a build-up of road dirt and belt
material that is not to be confused with wear.
The dirt can be removed with a suitable tool to check for
wear.
Clean, check, and reuse all pulleys in the front end
accessory drive if not damaged, rather than replacing.
Pulleys damaged from embedded debris MUST be
replaced.
Inspect the tensioner. Refer to Procedure 008-087 in
Section A.