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Freightliner Century Class. Manual - part 6

Verification of Inspections Log

Verification of Inspections Log, Groups 01, 20, and 49

Date

Mileage

Item

Cost

Maintenance Facility

Group 01 — Engine Noise Panels, Engine Mounts, and Engine-Support Fasteners

Group 20 — Fan Clutch

Group 49 — Exhaust System Components

General Information

Verification of Inspections Log: 00–11

00/21

MOP Number

Engine Drive Belt Inspection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 01–02

Engine Mount Inspection (Noise Emission Control) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 01–03

Engine Noise Panel Inspection (Noise Emission Control). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 01–01

Engine-Support Fasteners Check (Noise Emission Control) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 01–04

Safety Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 01–00

Engine

Index, Alphabetical

01–00 Safety Precautions

Safety Precautions in this section apply to all
procedures within this group.

DANGER

When working on the vehicle, shut down the en-
gine, set the parking brake, and chock the tires.
Before working under the vehicle, always place
jack stands under the frame rails to ensure the
vehicle can not drop. Failure to follow these steps
could result in serious personal injury or death.

01–01 Engine Noise Panel

Inspection (Noise
Emission Control)

If equipped, inspect for torn engine noise panels.
See

Fig. 1

for Caterpillar noise panel locations. If

panels are torn, replace them with new panels; see
Group 01 of the Century Class Trucks Workshop
Manual for procedures. Cummins M11 and N14 en-
gines, and Detroit Diesel Series 55 and Series 60
engines do not have engine noise panels.

01–02 Engine Drive Belt

Inspection

Worn or loose drive belts may cause premature
bearing failure or engine overheating. Excessive ten-
sion, or too little tension on the belt may result in ex-
cessive and premature belt wear. Poly-V belts, or
serpentine belts are retained by a belt tensioner that
requires no tension adjustment. Replace the belt if
any conditions described in "Visual Inspection" are
found. V-belts are installed as individual belts, and as
matched sets. When replacing matched sets of belts,
always replace both belts at the same time. Matched
belts must be from the same manufacturer. To in-
spect a belt, gently twist the belt to view the belt
sidewalls and bottom. Inspect all drive belts for the
following conditions, then perform the "Belt Tension
Inspection":

Visual Inspection

Inspect the belt for glazing. See

Fig. 2

, Ref. A.

Glazing is represented by shiny sidewalls, and is
caused by friction created when a loose belt slips
in the pulleys. It can also be caused by oil or
grease on the pulleys.

Check the belt for ply separation. See

Fig. 2

Ref. B. Oil, grease, or belt dressing can cause
the belt to fall apart in layers. Repair any oil or
coolant leaks that are affecting the belts before
replacing the drive belts. Do not use belt dress-
ing on any belt.

Check the belt for a jagged or streaked sidewall.
See

Fig. 2

, Ref. C. Jagged or streaked sidewalls

are the result of foreign objects, such as sand or
gravel in the pulley, or a rough pulley surface.

Check for tensile breaks; breaks in the cord
body. See

Fig. 2

, Ref. D. Cuts in a belt are usu-

ally caused by foreign objects in the pulley, or by
prying or forcing the belt during removal or instal-
lation.

Check for uneven ribs on serpentine (poly-V)
belts. See

Fig. 2

, Ref. E. Foreign objects in the

pulley will erode the undercord ribs, causing the
belt to lose its gripping power.

Check the drive belts for cracks. See

Fig. 2

, Ref.

F. Small irregular cracks are usually signs of an
old belt.

f011040

11/29/95

Oil Pan Noise Panel (C10 engine only)

Left-Side Noise Panel (3406 engine only)

Fig. 1, Caterpillar Engine Noise Panels

Engine

01/1

Inspect the pulleys for excessive play or wobble.
Excessive play or wobble indicates a failure of
the pulley bearing. Check for belt squealing or
squeaking. Replace bearings as needed.

NOTE: If it is difficult to distinguish the location
of a supposed bearing noise, place a stetho-
scope on the component being checked, not the
pulley, to isolate the area from outside interfer-
ence.

Inspect all pulleys for foreign objects, oil, or
grease in the grooves.

Belt Tension Inspection

Threaded-Adjustment Type

Apply the parking brakes, and chock the tires to
prevent the vehicle from moving.

Install a belt tension gauge at the center of the
belt’s longest free-span. Check belt tension. See

Table 1

for belt tension specifications.

If belt tension is not correct, see Group 01 of the
Century Class Trucks Workshop Manual.

Spring-Tension Type

On belts equipped with a spring tensioner, the belt
tension is automatically adjusted. Check that the ten-
sioner is holding tension on the belt by inserting the
end of a breaker bar in the 1/2-inch square hole on
the forward face of the tensioner, and rotating the
tensioner down, away from the belt. When the
breaker bar is slowly released, the tensioner should

return to its original position. If not, see Group 01 of
the Century Class Trucks Workshop Manual for re-
placement instructions.

f150010a

11/21/94

A. Glazing
B. Separating Layers

C. Streaked Sidewalls
D. Tensile Break

E. Uneven Ribs
F.

Cracks

Fig. 2, Drive Belt Replacement Conditions

Engine

01/2

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