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CLUTCH
11
1.5. MAINTENANCE, INSPECTION AND
TESTS
1.5.1. PRELIMINARY INSPECTION
Clutch needs replacement mainly on account of
clutch slippage or imperfect engagement and
disengagement. This may be due to worn out/
damaged clutch parts. It is desirable to carry out
the following preliminary checks before removal of
clutch for replacement if the parts.
CLUTCH SLIPPAGE TEST
Clutch slippage can be confirmed by any of the
following two methods:
1. Drive the vehicle in 1
st
or 2
nd
gear at
maximum speed corresponding to that gear.
With accelerator pedal fully pressed, apply
brake gradually with your left foot. If the
engine stalls, it means that clutch does not
slip.
2. Drive loaded vehicle in 3
rd
gear on level
ground and let the speed drop down to
approximately 15 Kmph / 9 mph. Now press
accelerator pedal fully. With slipping clutch,
the vehicle speed will not pick up and also
clutch burning smell will be noticed. If this
does not occur and vehicle picks up speed, it
indicates that clutch does not slip.
CLUTCH
ENGAGEMENT
AND
DISENGAGEMENT TEST
During the above test, when vehicle is in motion,
depress clutch pedal fully without changing the
accelerator pedal position. If the engine speed
increases
immediately,
perfect
clutch
disengagement is indicated. Further, release the
clutch pedal suddenly. If the vehicle moves
forward with a little jerk, perfect clutch
engagement is indicated.
CAUTION
This test should be carried out with utmost care
because sudden release of the clutch might cause
heavy jerk and damage to the clutch lining.
FACTORS AFFECTING CLUTCH WEAR
The clutch is designed to give maximum life under
most severe conditions when handled carefully.
However, while in operation, clutch lining is
subjected to wear. Apart from this the extent of
wear also depends on following.
A. PROPER MAINTENANCE
Improper maintenance may lead to clutch wear
and improper functioning.
Preventive Maintenance of clutch includes
checking oil level and bleeding the system for
defect free operation of clutch actuation
mechanism.
B. DRIVING
Following driving conditions will affect the
performance of the clutch.
1. CLUTCH RIDING
Using clutch pedal as a foot rest by keeping foot
constantly on pedal while driving will cause partial
clutch disengagement. It will result in slipping of
the clutch disc and premature failure of the clutch.
2. PERMITTING THE CLUTCH TO SLIP TOO
LONG
Half clutch driving and thereby permitting the
clutch purposely to slip too long will have the
same result as above.
3. PERMITTING THE CLUTCH TO JERK
Sudden clutch engagement at higher engine
speed specially while moving out the stuck vehicle
will cause severe instantaneous clutch loading,
resulting in clutch slippage and burning of the
lining locally. Starting the vehicle in first gear
under such conditions will avoid such problem.
Always propel the vehicle in first gear