1. Clutch System
Symptom Possible cause Corrective
1. Clutch slippage.
It is hard to perceive clutch slippage in
the early stage, but pay attention to the
following symptoms
Engine speed up when shifting.
High speed driving is impossible;
especially rapid acceleration impossible
and vehicle speed does not increase in
proportion to an increase in engine
Power falls, particularly when ascend-
ing a slope, and there is a smell of burn-
ing of the clutch facing.
Method of testing: Put the vehicle in
stationary condition with parking brake
fully applied. Disengage the clutch and
shift the transmission gear into the first.
Gradually allow the clutch to engage
while gradually increasing the engine
speed. The clutch function is satisfactory
if the engine stalls. However, the clutch
is slipping if the vehicle does not start off
and the engine does not stall.
(a) Clutch facing smeared by oil Replace.
(b) Worn clutch facing Replace.
(c) Deteriorated diaphragm spring Replace.
(d) Distorted pressure plate or flywheel Correct or replace.
(e) Defective clutch release bearing
Correct or replace.
2. Clutch drags.
As a symptom of this trouble, a harsh
scratching noise develops and control
becomes quite difficult when shifting
gears. The symptom becomes more
apparent when shifting into the first gear.
However, because much trouble of this
sort is due to defective synchronization
mechanism, carry out the test as
described after.
Method of testing: <Ref. to 2-10
It may be judged as insufficient disen-
gagement of clutch if any noise occurs
during this test.
(a) Worn or rusty clutch disc hub spline Replace clutch disc.
(b) Excessive deflection of clutch disc
Correct or replace.
(c) Seized crankshaft pilot needle bear-
(d) Cracked clutch disc facing Replace.
(e) Sticked clutch disc (smeared by oil or
3. Clutch chatters.
Clutch chattering is an unpleasant vibra-
tion to the whole body when the vehicle
is just started with clutch partially
(a) Adhesion of oil on the facing Replace clutch disc.
(b) Weak or broken torsion spring Replace clutch disc.
(c) Defective facing contact or excessive
Replace clutch disc defection.
(d) Warped pressure plate or flywheel Correct or replace.
(e) Loose disc rivets Replace clutch disc.
(f) Loose engine mounting Retighten or replace mounting.
(g) Improper adjustment of pitching stop-
4. Noisy clutch
Examine whether the noise is generated
when the clutch is disengaged, engaged,
or partially engaged.
(a) Broken, worn or unlubricated clutch
release bearing
Replace clutch release bearing.
(b) Insufficient lubrication of pilot bearing Apply grease.
(c) Loose clutch disc hub Replace clutch disc.
(d) Loose torsion spring retainer Replace clutch disc.
(e) Deteriorated or broken torsion spring Replace clutch disc.
1. Clutch System