General Diagnostic Table: Inspection: Clutch

WARNING: This page is about a different variant/trim than selected.

GENERAL DIAGNOSTIC CHART

Symptom	Possible cause	Corrective action
1. Clutch slippage It is hard to perceive clutch slippage in the early stage, but pay attention to the following symptoms. Engine speeds up when shifting. High-speed driving is impossible; especially rapid acceleration is impossible and vehicle speed does not increase in proportion to the increase in engine speed. Power falls, particularly when ascending a slope, and there is a smell of burning of the clutch facing. Method of testing: Put the vehicle in a stationary condition with parking brake fully applied. Disengage the clutch and shift the transmission gear into the 1st. 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	Rectify or replace.
	(e) Defective release bearing holder	Rectify 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 1st gear. However, because much trouble of this sort is due to defective synchronization mechanism, carry out the following tests. Method of testing: < Ref. to , DIAGNOSTIC DIAGRAM OF CLUTCH DRAG , INSPECTION, General Diagnostic Table. > It may be judged as insufficient disengagement 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 facing	Rectify or replace.
	(c) Stick of crankshaft pilot needle bearing	Replace.
	(d) Cracked clutch disc facing	Replace.
	(e) Stuck 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) Adhesion of oil on the facing	Replace clutch disc.
	(b) Weak or broken damper spring	Replace clutch disc.
	(c) Defective facing contact or excessively worn disc	Replace the defective clutch disc.
	(d) Warped pressure plate or flywheel	Rectify or replace.
	(e) Loose disc rivets	Replace clutch disc.
	(f) Loose engine mounting	Retighten or replace mounting.
	(g) Improper adjustment of pitching stopper	Adjustment.
4. Noisy clutch Examine whether the noise is generated when the clutch is disengaged, engaged, or partially engaged.	(a) Broken, worn or unlubricated release bearing	Replace the release bearing.
	(b) Insufficient lubrication of pilot bearing	Replace the pilot bearing.
	(c) Loose clutch disc hub	Replace clutch disc.
	(d) Loose damper spring retainer	Replace clutch disc.
	(e) Deteriorated or broken damper spring	Replace clutch disc.
5. Clutch grabs. When starting the vehicle with the clutch partially engaged, the clutch grabs 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 main shaft	Take off rust, apply grease or replace clutch disc or main shaft.
	(d) Deteriorated or broken damper spring	Replace clutch disc.
	(e) Loose engine mounting	Retighten or replace mounting.
	(f) Deteriorated diaphragm spring	Replace.