freightliner S2 Operator's Manual page 79

Report Erratic Clutch Operation Promptly
Reporting erratic clutch operation as soon as pos-
sible will give maintenance personnel a chance to
inspect the clutch components.
CAUTION
Operating the vehicle with incorrect clutch pedal
free-travel could result in clutch damage. See
Group 25 of the S2 Chassis Workshop Manual for
free-pedal adjustment procedures and specifica-
tions.
On mechanical clutch linkages, free-pedal travel
should be included and commented on daily in the
driver's report, since clutch free-pedal travel is the
best guide to the condition of the clutch and the re-
lease mechanism.
Clutch Wear
The major reason clutches wear out too soon is ex-
cessive heat. Clutches are designed to absorb and
dissipate more heat than encountered in typical op-
eration. The temperatures developed in typical op-
eration will not break down the clutch friction sur-
faces. However, if a clutch is slipped excessively or
required to do the job of a fluid coupling, high tem-
peratures develop quickly and destroy the clutch.
Temperatures generated between the flywheel,
driven discs, and pressure plates can be high
enough to cause the metal to flow and the friction
facing material to char and burn.
NOTICE
Do not allow sustained slippage of the clutch;
this could severely damage the clutch disc, pres-
sure plate, or flywheel. Damage caused by clutch
slippage due to improper break-in is not warrant-
able.
Slipping and excessive heat are practically nonexis-
tent when a clutch is fully engaged. But during the
moment of engagement, when the clutch is picking
up the load, it generates considerable heat. An incor-
rectly adjusted or slipping clutch will rapidly generate
sufficient heat to destroy itself.
The most important items that a driver should be
aware of to ensure long service life of the clutch in-
clude: starting in the right gear, recognizing clutch
malfunctions, and knowing when to adjust a clutch.
Clutch Adjustments
Some clutches have an internal adjustment. See the
applicable section in Group 25 of the S2 Chassis
Workshop Manual for clutch adjustment procedures
and specifications.
NOTICE
Operating the vehicle with the clutch incorrectly
adjusted could result in clutch or clutch brake
failure.
Clutch Lubrication
The release bearing should be lubricated at frequent
intervals. See Group 25 of the S2 Chassis Mainte-
nance Manual for intervals and procedures.
NOTICE
Failure to lubricate the release bearing as recom-
mended could result in release bearing damage
and damage to the clutch.
Transmission
10.8