Do not allow the RTV sealant to enter any blind threaded hole. If RTV sealant enters a blind threaded hole, it can 
cause hydraulic lock of the fastener when the fastener is tightened. Hydraulic lock of a fastener can lead to 
damage to the fastener and/or the components. Hydraulic lock of a fastener can also prevent the proper clamping 
loads to be obtained when the fastener is tightened. Improper clamping loads can prevent proper sealing of the 
components allowing leakage to occur. Preventing proper fastener tightening can allow the components to loosen 
or separate leading to extensive engine damage. 

 

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3.2 Clutch system 

3.2.1 Fastener specification 

3.2.1.1 Fastener Specifications 

Specification 

Fastener Name 

Model 

Metric (N.m) 

English system 

(lb-ft) 

Fixing bolt of clutch slave pump   

M8×1.25×25 

18～22 13.3～18.4 

Fixing bolt of clutch slave pump oil pipe 

bracket  

M8×1.25×16 

18～22 13.3～18.4 

Fixing bolt of clutch pressure plate and 

driven disc   

M8×1.25×14 

22～33 13.3～18.4 

3.2.1.2 General Specifications 

Specification 

Applications 

Metric（mm） 

English System 

(in) 

Outer diameter of clutch pressure plate   

276.5 

10.9 

Outer diameter of clutch driven plate   

230 

9.1 

Worn limiting value of Clutch driven disc (Rivet head depth) 

1.95±0.3 

0.077±0.011 

Flywheel Plane Runout (Interface of clutch drive disc ) 

0.7 

0.028 

3.2.2 Description and operation 

3.2.2.1 Description and operation 

The clutch assembly is located between the engine and the transmission, and is retained to the flywheel rear 
surface by fixing bolt . The clutch spline hub and transmission input shaft form rigid connections. During driving, 
the driver can press or release the clutch pedal according to requirement, to temporarily separate the engine and 
the transmission or gradually connect them in order to cut off or pass the input power from the engine to the 
transmission. Clutch system mainly includes the following components: 

z  Driving parts: Clutch pressure plate , Clutch pressure plate    is fixed on the flywheel by bolts. 

z  Driven parts: clutch disc with a spline hub. Spline hub slides freely along the input shaft in axial direction, 

and drives the input axis. Driving parts and driven parts maintain contact through spring pressure. The 
pressure is applied by the diaphragm spring in the pressure plate    assembly. 

z  Working parts: Clutch separation system consists of the clutch pedal, disengaging shaft, fork and Release 

bearings. When the clutch pedal is pressed, the Release bearings are pushed. Bearings then push the 
separation rod within the pressure plate and then the clutch is separated. 

 

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3.2.3 System operating principle 

3.2.3.1 System Operating Principle 

1.  Ensure vehicle smooth start: 

Before start, the vehicle is in stationary state. If the engine and transmission have a rigid connection, once a gear 
is engaged, vehicle will suddenly move forward because of the suddenly transmitted power. It will not only cause 
damage to mechanical parts, but also the driving force is not enough to overcome the enormous inertia caused by 
the forward force, so that the rapidly decrease in engine speed will shut down the engine. If a clutch is used when 
starting, the engine and transmission will be temporarily separated, and then the clutch will gradually engage. Due 
to the sliding between the clutch driving parts and the driven part, the torque transmitted from the clutch gradually 
increases from zero, while the vehicle driving force gradually increases, so that the vehicle starts smoothly.   

2.  Easy to shift: 

During driving, there is a need to frequently switch to different gears in order to adapt to changing driving 
conditions. If there is no clutch to temporarily separate the engine and transmission, then the transmission 
meshing gears will be hard to separate due to the unreleased load. In addition, gears with different circumferential 
speeds are difficult to mesh. Even if forced into the mesh, there will be a huge impact on tooth side and cause 
damage to parts. Use the clutch to temporarily separate the engine and transmission, then pressure between 
meshing surfaces of the original pair of gears will be greatly reduced due to load released, and thus they are easy 
to separate. For the other pairs of meshing gears, because the gear is separated from the engine and the inertia is 
small, it can make the gears meshing circumferential speed to be equal to or close to equal just using appropriate 
shifting action, so as to avoid or mitigate the impact between gears.   

3.  Prevent the transmission system overload: 

During emergency braking, the wheel speed suddenly decreases. Transmission system is connected to the engine 
and has the rotation inertia, so it remains the original speed, which generates a far greater inertia torque than the 
engine, causing damage to the powertrain parts. As the clutch relies on friction to transmit torque, so when the 
transmission system load exceeds the friction torque, the clutch drive parts and driven parts will skid, thus to 
prevent the overload. 

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3.2.4 Disassemble drawings 

3.2.4.1 Clutch control mechanism 

2

2

9

8

11

4

12

3

5

6

10

7

1

NL03-0004c

 

1.  Oil outlet pipe assembly of master pump   

2.  Fixing nut of clutch master pump 

3. Pin 

axle 

 

4.  Pin axle lockpin 

5.  Clutch pedal mounting nolt 

6. Clutch 

pedal 

 

7.  Clutch pedal mounting nut 

8.  Clutch pedal return spring 

9.  Clutch pedal support 

10.  Oil Inlet hose for master pump 

11.  Retaining clamp for oil inlet hose for master 

pump 

12.  Clutch master pump assebmly 

 

 

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