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
IEngine revs up when shifting.
IHigh speed driving is impossible; especially rapid
acceleration impossible and vehicle speed does not
increase in proportion to an increase in engine speed.
IPower falls, particularly when ascending a slope,
and there is a smell of burning of the clutch facing.
IMethod of testing: Put the vehicle in stationary con-
dition 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) No clutch pedal play Readjust.
(b) No release lever end play Readjust.
(c) Clutch facing smeared by oil Replace.
(d) Worn clutch facing Replace.
(e) Deteriorated diaphragm spring Replace.
(f) Distorted pressure plate or flywheel Correct or replace.
(g) Defective release bearing holder Correct or replace.
(h) Defective pedal and cable system 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 the this sort is due to defective syn-
chronization mechanism, carry out the test as
described after.
It may be judged as insufficient disengagement of
clutch if any noise occurs during this test.(a) Excessive clutch pedal play Readjust.
(b) Excessive clutch release lever play Readjust.
(c) Worn or rusty clutch disc hub spline Replace clutch disc.
(d) Excessive deflection of clutch disc
facingCorrect or replace.
(e) Seized crankshaft pilot needle bearing Replace.
(f) Malfunction of pedal and cable system Correct or replace.
(g) Cracked clutch disc facing Replace.
(h) Sticked clutch disc (smeared by oil or
water)Replace.
3. Clutch chatters.
Clutch chattering is an unpleasant vibration to the
whole body when the vehicle is just started with clutch
partially engaged.(a) Improper clutch cable routing Correct.
(b) Adhesion of oil on the facing Replace clutch disc.
(c) Weak or broken torsion spring Replace clutch disc.
(d) Defective facing contact or excessive
discReplace clutch disc defec-
tion.
(e) Warped pressure plate or flywheel Correct or replace.
(f) Loose disc rivets Replace clutch disc.
(g) Loose engine mounting Retighten or replace
mounting.
(h) Improper adjustment of pitching stop-
perAdjustment.
4. Noisy clutch
Examine whether the noise is generated when the
clutch is disengaged, engaged, or partially engaged.(a) Broken, worn or unlubricated release
bearingReplace 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.
5. Clutch grabs.
When starting the vehicle with the clutch partially
engaged, the clutch engages suddenly and the vehicle
jumps instead of making a smooth start.(a) Grease or oil on facing Replace clutch disc.
(b) Deteriorated cushioning spring Replace clutch disc.
(c) Worn or rusted spline of clutch disc or
mainTake off rust, apply
grease or replace clutch
shaft disc or mainshaft.
(d) Deteriorated or broken torsion spring Replace clutch disc.
(e) Loose engine mounting Retighten or replace
mounting.
(f) Deteriorated diaphragm spring Replace.
19
[K100]2-10DIAGNOSTICS
1. Clutch System
