1. Clutch slippage It is hard to perceive clutch slippage in the early stage, but pay attention to the following symptoms. • Engine temporarily speeds up when the accelerator ON immediately after shifting. • High-speed driving is not possible; especially rapid acceleration is not possible and vehicle speed does not increase in proportion to the increase in engine speed. • Power drops particularly when ascending a slope, and there is a burning smell of the clutch plate. • Method of testing: Park the vehicle and fully apply the parking brake. Disengage the clutch and shift the transmission gear into the 1st. Gradually increase the engine speed while gradually allowing the clutch to engage. The clutch function is satisfactory if the engine stalls. However, the clutch is slipping if the vehicle does not move forward and the engine does not stall. | (a) Oil on the clutch face | Replace. |
(b) Worn clutch face | Replace. |
(c) Deteriorated diaphragm spring | Replace. |
(d) Warped pressure plate or flywheel | Repair or replace. |
(e) Defective release bearing holder | Repair or replace. |
2. Clutch drags. As a symptom of this trouble, a harsh scratching noise occurs and control becomes difficult when shifting gears. The symptom becomes more apparent when shifting into the 1st gear. However, because most trouble of this sort is due to a defective synchronization mechanism, perform the following tests. • Method of testing: General Diagnostic Table > INSPECTION The problem is caused by insufficient disengagement of the clutch if an abnormal noise occurs during this test. | (a) Worn or rusty clutch disc hub spline | Replace the clutch disc. |
(b) Excessive deflection of clutch disc face | Repair or replace. |
(c) Crankshaft pilot needle bearing sticking | Replace. |
(d) Cracked clutch disc face | Replace. |
(e) Stuck clutch disc (smeared by oil or water) | Replace. |
3. Clutch chatters. Clutch chattering is an unpleasant vibration to the whole vehicle when the vehicle is just started with clutch partially engaged. | (a) Adhesion of oil on the clutch face | Replace the clutch disc. |
(b) Weak or broken damper spring | Replace the clutch disc. |
(c) Poor contact of the disc surface or excessively worn disc | Replace the faulty clutch disc. |
(d) Warped pressure plate or flywheel | Repair or replace. |
(e) Loose disc rivets | Replace the clutch disc. |
(f) Loose engine mounting | Retighten or replace mounting. |
4. Noisy clutch Examine whether the noise is generated when the clutch is disengaged, engaged, or partially engaged. | (a) Broken, worn or insufficiently lubricated release bearing | Replace the release bearing. |
(b) Insufficient lubrication of the pilot bearing | Replace the pilot bearing. |
(c) Loose clutch disc hub | Replace the clutch disc. |
(d) Loose damper spring retainer | Replace the clutch disc. |
(e) Deteriorated or broken damper spring | Replace the clutch disc. |
5. Clutch grabs suddenly. 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 the clutch disc. |
(b) Deteriorated cushioning spring | Replace the 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 the clutch disc. |
(e) Loose engine mounting | Retighten or replace mounting. |
(f) Deteriorated diaphragm spring | Replace. |
Clutch fluid air bleeding procedure
