3.3.3 System operating principle 

3.3.3.1 Gearshift operating principle 

V5A1A type Transmission assembly is 5-gear Manual transmission. Gear shifter drives flexible shaft of selector 
to select gears of transmission. 

3.3.3.2 Operating principle of odometer sensor 

Vehicle speed sensor is a hall sensor, installed on the drive gear shaft. When the transmission main shaft rotates, 
the vehicle speed sensor operates, so that the vehicle speed sensor generates signals and sends the signal to the 
instrument panel. 

3.3.3.3 Reverse lamp switch operating principle 

Reverse lamp switch is a normally open switch. When the reverse gear is engaged, the reverse fork will squeeze 
reverse switch contact, making reverse lamp switch closed, then the reverse lamp circuit is completed and reverse 
lamp is lit. 

 

 

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3.3.4 Component position   

3.3.4.1 Transmission assembly position   

NL03-1001e

 

 

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3.3.4.2 Vehicle speed sensor, reverse switch position   

1

2

3

4

GC03-0004c

 

1.  Vehicle speed sensor 

2. Reverse 

switch

 

3. Drain 

hole 

4.  Filling hole of transmission oil   

 

 

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3.3.5 Diagnostic information and procedures 

3.3.5.1 Diagnosis descriptions 

Refer to 3.3.2 Description and operation, get familiar with the system functions and operation before starting 
system diagnosis, so that it will help to determine the correct diagnostic procedures, more importantly, it will also 
help to determine whether the situation described by the customer is normal. 

3.3.5.2 Visual inspection 

Common malfunctions of transmission are: hard to shift, gear stuck, gear collision and grinding abnormal sound. 
The clutch, drive system malfunction can also cause the above faults. During maintenance, we need carefully 
analyze and distinguish. 

Prior to repairing, carry out general inspection of the transmission and clutch: 

z  Check transmission, clutch pipe for oil seeping. 

z  Inspect the transmission oil level, transmission oil viscosity and color, and then inspect for dirt and metal 

debris to determine whether there have been internal components stuck, burning or broken. 

z  Check transmission and the surrounding components. Check for bolts and nuts loosening or falling off; 

z  Road test and engage gears to confirm the vehicle conditions for further diagnosis. 

Before repairing the transmission abnormal sound, distinguish the clutch, drive shaft, and the engine abnormal 
sound, and exclude the external factors that may generate abnormal sound and noise. 

Before repairing the transmission abnormal sound, identify the following items: 

z  Road Noise 

Such as noise generated from tires, road, wheel bearings, engine and exhaust system. The noise varies due to 
vehicle dimension, type and body insulation materials, etc. 

z  Drive shaft system noise 

As a mechanical device, drive axle system can not be without sound during the operation. There will be some 
sound during the operation. Confirm the abnormal noise: 

1.  Choose a good road surface to reduce tires friction and body vibration generated noise. 

2.  Drive a distance long enough to completely warm up the lubrication oil. 

3.  Record speed and transmission gear when the noise occurs. 

4.  Determine whether there is noise when driving the vehicle in the following conditions: 

z  Slow acceleration or sudden acceleration; 

z  On an even road, keep the throttle slightly open and maintain constant speed when driving; 

z  Transmission is put in gear and the throttle closed when cruising. 

5.  Stop vehicle and shut down the engine, whether there is abnormal sound. 

z  Bearing Noise 

1.  Differential gear or bearing noise 

Noise of bearings on differential side and the wheel bearing noise is likely to be mixed up. As the 
differential bearings have a pre-load force, even if the wheels leave the road, as long as the differential 
and drive shaft are in operation, the differential bearings noise will not be significantly reduced. 

2.  Wheel bearing noise 

When the transmission is in neutral gear and the vehicle is sliding, the wheel bearing issue a continuous 
roar or friction sound. Since there is no wheel bearing pre-load force, when the wheels leave the ground 
the wheel bearing noise will be significantly reduced. 

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