Trouble-shooting a faulty clutch

Symptoms and probable causes

1. Slippage

The clutch slipping will appear gradually with the followings.

a. No speed gain

b. Fuel consumption increases

c. Engine overheats

d. Not enough acceleration relative to engine rpm when the accelerating

pedal is depressed suddenly

e. Loss in power is evident when climbing a slope

The clutch slippage can be detected immediately in case of “d” and “e”,

but as for the symptoms of “a”, “b” and “c”, they are sometimes taken

for engine troubles. Thus, diagnosis must be carefully made. Try not

to operate the car with a slipping clutch which may lead to excessive wear

or burning of clutch facing.

INSPECTION: Pull the parking brake fully and lock the wheels completely.
Disengage the clutch by depressing clutch pedal, then engage

transmission gear in the first speed position. Slowly engage the clutch

while increasing the engine rpm gradually. If the engine begins to stall,

the clutch is in good condition. If the car does not move and the engine

does not stall, the clutch is slipping.

a. No clutch pedal play	Adjust
b. No play at release fork end	Adjust
c. Oil adhering to clutch facing	Replace
d. Clutch facing worn out	Replace
e. Weak compression spring	Replace
f . Deformed pressure plate and/or flywheel	Repair or replace

2. Improper Disengagement

This symptom causes unpleasant noise (crunch) when shifting the trans-

mission gears into mesh, and makes the gearshift difficult. Especially this

appears when shifting into low gears.

INSPECTION: Depress the clutch pedal and engage the gears, next

position in neutral. Accelerate the engine, then engage the gears again.

At this time keep the clutch pedal depressed. If the noise is still present,

the clutch may be defective.

a. Excessive clutch pedal play	Adjust
b. Excessive play at release fork end	Adjust
c. Defective input shaft front bearing	Replace
d. Worn splines of clutch disc hub	Replace disc assembly
e. Excessive clutch disc run-out	Repair or replace
f . Weak or deformed master cylinder piston cup	Replace piston cup or complete master cylinder
g. Fluid leakage from master cylinder piston gasket	Replace gasket or complete master cylinder
h. Fluid leakage from release cylinder piston gasket	Replace gasket or complete master cylinder
i . Air in clutch hydraulic system	Bleed air

3. Chattering

Upon starting out the car with the clutch engaged half-way, entire body

may vibrate.

a. Clutch facing glazed	Recondition the facing with sandpaper or replace
b. Oil on facing	Replace
c. Damaged or weak disc torsion rubbers	Replace disc assembly
d. Poor facing contact or excessive disc run-out	Replace disc assembly
e. Warped pressure plate or flywheel	Repair or replace
f . Loose engine mounting	Tighten or replace
g. Loose rivets in clutch disc	Replace

4. Noisy

Find the origin of the noisy clutch by disengaging the clutch “a” and “b”,

engaging clutch “c” , “d” and “e” .

a. Damaged, worn or improperly lubricated release bearing	Replace
b. Damaged or worn input shaft front bearing	Replace
c. Loose disc hub	Replace disc assembly
d. Cracked disc plate	Replace disc assembly
e. Weak or damaged disc torsion rubbers	Replace disc assembly

5. Jerking

Upon starting out the car with the clutch engaged half-way, the car jerks

and is not accelerated smoothly.

a. Oil on facing	Replace
b. Worn facing or loose rivets	Replace disc assembly
c. Damaged or weak disc torsion rubbers	Replace disc assembly