Noise Diagnosis; Accessory Drive Belt Diagnosis Chart - Mercedes-Benz 2005 Sprinter Service Manual

7 - 6 ACCESSORY DRIVE
DRIVE BELTS (Continued)
Refer to ACCESSORY DRIVE BELT DIAGNOSIS
CHART for further belt diagnosis.

NOISE DIAGNOSIS

Noises generated by the accessory drive belt are
most noticeable at idle. Before replacing a belt to
CONDITION
RIB CHUNKING (One or more ribs
has separated from belt body)
RIB OR BELT WEAR
BELT SLIPS
LONGITUDAL BELT CRACKING
GROOVE JUMPING
(Belt does not maintain correct
position on pulley)

ACCESSORY DRIVE BELT DIAGNOSIS CHART

POSSIBLE CAUSES
1. Foreign objects imbedded in
pulley grooves.
2. Installation damage
1. Pulley misaligned
2. Abrasive environment
3. Rusted pulley(s)
4. Sharp or jagged pulley groove
tips
5. Belt rubber deteriorated
1. Belt slipping because of
insufficient tension
2. Belt or pulley exposed to
substance that has reduced friction
(belt dressing, oil, ethylene glycol)
3. Driven component bearing failure
(seizure)
4. Belt glazed or hardened from
heat and excessive slippage
1. Belt has mistracked from pulley
groove
2. Pulley groove tip has worn away
rubber to tensile member
1. Incorrect belt tension
2. Pulley(s) not within design
tolerance
3. Foreign object(s) in grooves
4. Pulley misalignment
5. Belt cordline is broken
resolve a noise condition, inspect all of the accessory
drive pulleys for contamination, alignment, glazing,
or excessive end play.
1. Remove foreign objects from
pulley grooves. Replace belt.
2. Replace belt
1. Align pulley(s)
2. Clean pulley(s). Replace belt if
necessary
3. Clean rust from pulley(s)
4. Replace pulley. Inspect belt.
5. Replace belt
1. Inspect/Replace tensioner if
necessary
2. Replace belt and clean pulleys
3. Replace faulty component or
bearing
4. Replace belt.
1. Replace belt
2. Replace belt
1. Inspect/Replace tensioner if
necessary
2. Replace pulley(s)
3. Remove foreign objects from
grooves
4. Align component
5. Replace belt
VA
CORRECTION