Drive Belts; Drive Belt; Serpentine Belt; Inspection - Mercury 4.2 Diesel Operation & Maintenance Manual

Section 4 - Maintenance

Drive Belts

Drive Belt

All drive belts must be periodically inspected for tension and condition, such as excessive wear, cracks, fraying, or glazed
surfaces.
Inspecting the belts with the engine running may cause serious injury or death. Turn off the engine and remove the ignition
key before adjusting tension or inspecting belts.
a
e

Serpentine Belt

Inspection

1. Inspect the belt for proper tension and for the following:
• Excessive wear
• Cracks
NOTE: Minor, transverse cracks (across the belt width) may be acceptable. Longitudinal cracks (in the direction of
belt length) that join transverse cracks are not acceptable.
• Fraying
• Glazed surfaces
2. Check the operation of the automatic tensioner and associated components.
a. Position a suitable tool in the automatic tensioner release slot.
Page 64
WARNING
!
4.2 inboard shown, 2.8 similar
a - Water circulating pump pulley
b
b - Alternator pulley
c - Idler
c
d - Automatic Tensioner
e - Crankshaft pulley
f - Seawater pump pulley
d
g -

Serpentine belt

f
g
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21062
90-8M0113988 DECEMBER 2015
eng