Engine
For the structure and main technical parameter of engine see Table 2.
Table 2 Structure and main technical parameter of engine
Serial No. Item Specification and parameter
1 model 4G64S4M
2 style 4-cylinder, straight-line, water-cooling, single top
cam shaft, 4-stroke engine
3 Fuel oil supply method Multi-point fuel oil injection(MPI)
4 Measuring method of inlet capacity Speed compact style
5 Combustion room style Single-slope roof
6 Cylinder diameter × stroke(mm) 86.5×100
7 Total displacement (L) 2.351
8 Compression ratio 9.5:1
9 Max. power and corresponding speed (kW/r/min) 93/5250
10 Max. torque and corresponding speed (N·m/rpm) 190/2500
11 Min. fuel consumption (g/kW·h) ≤254
12 Idle stable speed(r/min) 750±30
13 Idle-speed control Electronic closed loop control
14 Mean piston speed(m/s) 17.5
15 Mean effective pressure (kPa) 1036
1 6 C y l i n d e r c o m p r e s s i o n p r e s s u r e : i n 250r/min (kPa) 1 3 2 0
17 Ignition sequence and control 1-3-4-2; without distributor block, electronic
controlled direct ignition
18 Spark plug gap(mm) 1.0~1.1
19 Spark plug model BKR5E-11 or K16PR-U11 or RC10YC4
BKR6E-11 or K20PR-U11 or RC8
20 Manufacturer of spark plug NGK or DENSO or Xiang huo ju
21 Valve clearance(mm) 0(hydraulic column )
22 Port timing: Opened inlet/closed inlet
Opened outlet/closed outlet 18 °before upper stop point/ 53 °after lower stop
point
50°before lower stop point/ 18 °after upper stop
point
23 Lubrication method Combined method of pressure and splash
24 Pressure of engine oil of main oil channel, in idle
speed of 3000rpm (kPa) (≥78.5)/(245-490)
25 Max. engine oil temperature(℃) 130
26 Consumption ratio of engine oil(g/kW·h) 2
Overview of the entire car-5
The friction, disc, single-diaphragm spring clutch, hydraulic control mechanism. The external diameter of friction disc D=225mm,
internal diameter d=150mm, material is F810.
Adjustment of clutch pedal:
1. Measure the height of clutch pedal (from pedal pad surface to floor) and free stroke of clutch pedal (fork bar pin clearance).
Standard height of clutch pedal: flush with the brake pedal, free stroke of clutch pedal is 5-15mm;
2. Readjust the free stroke of pedal after adjust the height of pedal; rotate the push bar to the standard value, then fix the bolt
and nut;
3. If the free stroke of clutch pedal is not within standard value, it should rotate the adjusting bolt to standard value, then fix
the bolt and nut. Do not move the push bar to main cylinder when adjust the free stroke of pedal;
4. If the free stroke of clutch pedal and clearance between the clutch pedal and floor when the clutch is disengaged de not
consist with the standard, this may by caused by the air in hydraulic system and failure of main cylinder or clutch. It can
discharge the air of system or dissemble and inspect the main cylinder or clutch.
Table 2 Structure and main technical parameter of engine(continued)
Serial No. Item Specification and parameter
27 Consumption ratio of engine oil and fuel oil
(%) ≤0.8
28 Cooling method Closed forced water cooling
29 Starting method Electric motor
30 Net weight(kg) 167
31 Outline dimension: L×W×H (mm) 730×653×667
32 Idle-speed emission CO(%)/HC(ppm) ≤0.5/≤100
33 Emission control degree of operating
condition regulation With three unique catalytic converter, air-fuel
ratio closed loop control, the equipped light
car meets the standard of GB 18352.2-
2001
Air inlet system
Dry-type air cleaner.
Exhaust air system
Primary muffler, with two-stage three-way catalyst device.
Fuel supply system
Adjustment of accelerator pedal
The stroke of accelerator pedal is 155mm; adjust the adjusting nut on wire bracket if it does not consist with the standard.
The fuel tank is plastic tank with capacity of 67L; the oil supply control is the mechanical pedal oil control and
internal-type electric fuel pump; the type of fuel evaporation is the activated carbon can and electric valve control.
Cooling system
Forced circulation water cooling, electric fan and aluminum tube radiator.
Clutch
Overview of the entire car-7
Suspension
The front suspension is the torsion bar spring, double-cylinder inflatable hydraulic damper, transverse stabilizer rod, double
cross-arm independent suspension. The distance between the center of front shaft of lower arm fixing nut and level ground is
295mm±1mm.
The rear suspension is the four-connecting rod, coil spring, double-cylinder inflatable hydraulic damper, transverse stabilizer
rod, no indep endent suspension.
Carriage
Peripheral trapezoidal structure; welded by two box section longitudinal beams and several box or tube section cross beams.
Steering system
Pinion-and-rack power steering-gear, hydraulic assists steering. Breakaway front steering trapezoidal structure. Diameter of
quadriradistus steering disc φ380mm, adjustable angle, power-absorbing steering pipe. For main technical parameters of
steering s ystem refer to Table 5.
Table 5 Main technical parameter of steering system
Serial No. Item Parameter Serial No. Item Parameter
1 wheel camber 0°±30′ 6 Rotary round of
steering disc n 3.64
2 kingpin inclination 12°30′±30′ 7 Angle drive ratio of
steering system i0ω 18.2
3 kingpin castor 3°30′±30′ 8 Force drive ratio of
steering s ystem i0p 198.0
4 toe (mm) 0~2 9 Normal efficiency of
steering gear η+ ≥75%
5 Steering angle of
internal and external
wheel (°) 32/28 10 Revers e efficiency of
steering gear η- ≥60%
1.Adjustment of .4-Wheel Alignment
Test and adjust the front wheel alignment value and adjust the toe on the 4-Wheel Alignment meter.
a. Adjustment of kingpin castor: The standard value is 3°30′±30′(adjust the difference of left and right kingpin
castor to within 30′);
b. Adjustment of toe: The toe with standard value of 0~2mm is adjusted by rotating the steering cross rod. When adjust
the toe, it should rotate the cross brace in left and right side evenly. Tighten the lock nut after adjustment, the torque is
55 - 65N·m.
c. Centering and fix of steering wheel: according to the display of the alignment gauge, turn the front wheel to right
ahead, after removing the steering wheel without changing the position of steering lever, mount the steering wheel
with center aligned, the radials of the steering wheel shall be in the bilateral symmetry position, and the symbol of
Great wall on the steering wheel shall be in the confrontation position of the driver, tighten the nut, with a tightening
torque of 25 - 35N·m.
Left wheel left steering: 32, right wheel left steering:28;
Left wheel right steering:
28, right wheel right steering: 32;
b. Under the light condition of the car, the height between the center of front axis fixed bolt of the lower suspension arm to the
ground is 295
1mm, if the dimension is not within this scope, reach it through adjusting the torsion bar adjustment arm
bolt;
c. The reference dimension of the height of the car is : the left and right deviation is less than 10mm;
3. Checking the free gap of steering wheel:
Turn the orientation of the car to front, stop the engine, exert a force of about 4.9N on the steering wheel along the circumferential
direction to make the it turning to the left, there is resistance force, stop turning when the resistance force is growing; then turn
the steering wheel to the right, stop turning when the resistance force is felt to be growing; the radian value that the external edge
of steering wheel runs is the free gap of the steering wheel, its standard value shall be less than or equal to 20
, and the corner
from the central position to the left or right shall be no larger than 10.
Brake system
The front wheel brake is ventilation coil type, the rear wheel brake is disk and drum type. The service brake type is that the double-
loop vacuum assist hydraulic brake is applied on the front and rear disc brake. The parking brake is mechanical dragline acting on the
drum brake of the rear wheel.
The free stroke of brake pedal is 20mm
30mm, and the operating stroke of the pedal is 120mm. The operating stroke of the brake
handle is 17
(3 teeth)30(8 teeth).
1. The adjustment of brake pedal
Measure the operating stroke of the brake pedal, the standard value is 120mm. When the eighth is no in compliance with the
requirement, make adjustment according to the following procedures:
a. Separate the brake lamp switch wire connector, loosen the blocking nut, and turn the brake lamp switch to the position that the
stopper is not touched;
b. Unscrew the blocking nut of the operation connecting rod, use the thinnose pliers to turn the operation connecting rod, adjust
the brake pedal height to standard value, after reaching the standard value, tighten the lock nut;
c. Turn the brake lamp switch to the position that the stopper of brake pedal is just touched, continue the turning for 1/2
1 circle,
and tighten the blocking nut;
d. Connect the brake lamp switch wire connector;
e. The brake lamp should not be light when the brake pedal is in release status.
2. Standard value of brake pedal free stroke: 20-30 mm
a. Under the stopping status of the engine, step on the brake pedal for 2
3 times, clear the influence of brake assistor, then use
hand to push the brake pedal to the position that there is resistance, measure the amount of movement (free stroke). It shall
be in compliance with the regulation of standard value;
b. If the gap is less than the regulation value, check to see whether the gap between the carrier rod of brake lamp switch and the
brake pedal is in compliance with the regulation. If this gap is exceeding the regulation, it means that the gap between the drive
rod clevis pin and the brake pedal arm is exceeding the regulated value.
3. Start the engine, step down the brake pedal with a force of about 700N,ehck the main brake pump, whether there is oil
leakage on the connection positions of the brake pipeline. If there is, maintain it.
4. Operating status test of brake assistor
Conduct the operation status test of the brake assistor according to the following methods:
a. Start the engine, stop if after operating for 1
2 minutes. Step on the brake pedal for several times with normal force. Expect
that the pedal can be fully stepped down a the first stepping, the height of the brake pedal shall be raised on and on with the
stepping, thus means that the brake assistor operates normally, if the height of the pedal is not changed, it means that the brake
assistor is damaged;
b. Under the stopping status of the engine, step on the brake pedal for several times, confirms that the height of brake pedal is
elevated on and on, under the status that the brake pedal is stepped down, start the engine. At this time, the brake pedal will
move down a bit, it means that the brake assistor is working normally. If the brake pedal is moving upwards, it means that the
brake assistor is damaged;
c. Under the operation status of the engine, step down the brake pedal to stop the operation of the engine. AT this time, the there
shall be no change of the height of brake pedal within 30 seconds, it means that the brake assistor is working normally. If the
brake pedal is moving upwards, it means that the brake pedal assistor is damaged.
5. Adjustment of the parking brake system:
a.For positioning, pull the brake bar to the limit position for over 3 times, use a force of about 400N to pull the brake parking
lever, count the number of knocking teeth. The standard value of stroke of parking brake : 17
(3 teeth) 30(8 teeth);
b.If the stroke of brake parking lever is too big and not in compliance with the requirement, adjust it with the following methods:
Loosen the brake parking lever, unscrew the adjusting nut.
Remove the adjuster hole cap from the brake assembly, use screwdriver to turn the adjustor in the arrow direction to the limit
that the brake drum cannot turn.
Rotate 5 teeth in the counter arrow direction.
Rotate the adjusting nut, adjust the brake parking lever stroke to the standard value.
c. If the stroke is less than the standard value, unscrew the adjusting nut to make it reach the standard value.
d. Check to see whether the adjusting nut and the rod are loosened, whether the adjusting nut is fixed in the fixed seat.
e. After adjustment, jack up the rear part of the car. Loosen the brake parking lever, the brake disc shall not be dragged when
checking the rear wheel.
f. The breaking in of the parking brake: use the force of about 200-250N to pull the brake parking lever,drive the car for about
400m with a speed of about 60km/h, repeat for 2-3 times, then test on the slope of 30%, the car shall be able to be parked.
Clutch-2
Troubleshooting
failure cause inspection content
Shift difficulty or can not shift
Large free stroke of clut ch pedal clutch Pipe
has air
Failure of clutch cylinder
Failure of clutch master cylinder
The installation position of clutch disc is not
in position; large deviation; oil on the friction
lining or broken
The clutch disc is dirty or with foreign
material
Failure of clutch cover Adjust the free stroke of pedal
Discharge the air in clutch system
Replace
replace
Inspect the clutch disc; replace
Repair if necessary
Replace
Disengagement of transmission The clutch guide bearing is worn. Replace the guide bearing
Slide of clut ch
insufficient free stroke of clutch pedal
oil on the clutch disc friction lining or broken
failure of press disc
separation rocker arm assembly is blocked Adjust the free stroke of pedal
Inspect the clutch disc and replace it
Replace the clut ch cover
Check the separation rocker arm assembly
clutch clamping
stagnation/vibration oil on the clutch disc friction lining or broken
failure of press disc clutch membrane spring
is bend
loose of engine bracket Inspect the clutch disc and replace
Replace the clut ch cover
Correct the clutch membrane
Repair if necessary
Soft of clutch pedal clutch pip e has air
failure of clutch cylinder
failure of clutch master cylinder Discharge the air in clutch
replace
replace
Loud noise of clut ch
Component in clutch housing is loose
Throw-out bearing is worn or dirty
guide bearing is worn
separation rocker arm assembly or pull-rod is
blocked Repair if necessary
replace
replace
Repair if necessary
Automatic transmission-2
Instruction for automatic transmission
1. M88 4-speed automatic transmission is equipped with the hydraulic torque converter and electric control system with locking.
When keep the stable forward status, the hydraulic torque converter can be locked automatically when the engine operates in low
speed, then reduce the unnecessary slide.
Figure 1.1 Electric automatic transmission control system
Figure 1.2 M88 4 speeds automatic transmission appearance figure (applied to 2 wheels driving)
2. The main advantage of the transmission is the application of transmission control unit (TCU). The control unit is the control
system based on the microprocessor system.. TCU control the shifting sensing and realize the Gear position shifting through the
signal of opening degree of throttle position, opening frequency of throttle position, engine speed, vehicle speed, transmission oil
temperature, gear position, mode selection and forced Gear reduction application.
3. TCU drives a variable pressure regulating solenoid valve to control three regulation valves and control the feeling of shifting.
Different transmission fluid temperatures are taken as one the main parameters to control the output pressure of the solenoid
valve, so as to keep consistent feeling of shifting within the normal operation scope.
4. The planning of shifting is very flexible. According to the car model, the different shifting plan is stored in the same TCU.
Generally speaking, the “economical mode” can increase the economical efficiency of the fuel and the driving performance of the
car to the maximum limit. The “dynamic mode” can bring into full play the drive performance of the car to the maximum limit. The
“winter mode” can make the car starting from shift 2.
Automatic transmission-4
10. The gross weight of the transmission is 76kg; mostly weight is on the front of the transmission (side of torque converter). This
should be considered when design the handling/assembly tools.
11. The crankshaft speed/position sensor is installed on the top of transmission torque converter housing which must be installed
after the transmission is installed on the engine. The sensor will be damaged if it is installed before the installation of
transmission.
12. The transmission use the breathing tube connected to rear end of transmission. The tube must not be restricted or blocked
otherwise the air pressure in transmission will be increased. It is unallowable that the water/dirty/dust enters into the
breathing tube; otherwise the transmission will be damaged.
Removal of transmission
If the transmission needs removing for any reasons, following is the preventive measure to help the remove.
1. Must not only support the oil pan in middle of transmission for it will be deformed and leaked. The oil pan will not be deformed
when supports its external edge.
2. It must not allow the transmission to connect to the engine when the rear end is without connection, otherwise the exhaust
system of vehicle will be damaged.
3. Remove all torque converter bolts and push back the torque converter before remove the bolt connected the torque converter
housing to engine. Once all bolts connected the torque converter housing to engine are removed, use the torque converter the
push the transmission from the location pin, then ensure the torque converter is on the transmission and the transmission is
separated form location pin.
4. Install the dustproof cover on the cooler connector rapidly after open the oil cooler pipe; otherwise the oil leakage from the
torque converter will be 2L. The odometer dustproof cover can prevent the dirty from entering into the transmission and avoids
the leakage of oil form transmission.
5. The engine speed sensor is installed on the top of transmission and should be removed before the transmission is removed form
the engine, for the sensor will be damaged during the removal process of the transmission.
Figure 2.1 Gear selection interface
mode selection
gear selection
indicationgear slide way
Operation and display interface
The four-speed automatic transmission has three types of operation display interface which are shown as follows:
Gear selection
The transmission uses the traditional gear selection shifting handle, which is shown in figure. The gear rod can be moved on the gear
slide way according to the requirement. The relationship between the related gear and its function.
Automatic transmission-13
Symbol of solenoid valve (On/off solenoid valve)
Figure 3.5 Normal-opened type
1.Variable pressure regulating valve regulating system
The shifting pressure of abrasion unit is controlled by the variable pressure regulating valve.
The line pressure is independent of the shifting pressure and determined by the thro
position, shifting status and engine speed.
S5 is a proportional or variable pressure regulating valve which provides the pressure signal control shifting pressure for
the clutch and brake belt regulating valve.
In automatic shifting period, it process the integral times enlarging and contracting
regulation for the clutch regulating valve, brake belt regulating valve, torque converter regulating valve and VPS.
The hydraulic pressure generated by variable pressure regulating valve is in inverse ratio with current. During the shifting, TCU
will increase or decrease the current of solenoid valve according to the program. The current is variable in the range of 200mA
to 1000mA. The increasing of the current will decrease the S5 output pressure; the decreasing of current will increase the output
pressure of S5.
Lin 500 pressure (about 440 to 560kPa) is the reference pressure of VPS, meanwhile, the VPS output pressure equals to the
pressure on line 500 always.
When the VPS is in waiting status, it means there is not the generation of shifting action. VPS current is 200mA. At this time,
it gives the maximum output pressure.
In stable status, the brake belt and clutch regulating solenoid valve is in closed status. In this condition, the pressure of line 500
is applied on the piston. For the line 500 pressure is more than S5 pressure always, so it pushed the oil in S5 to the place
between the regulating valve and piston. At this time, oil pressure applied on the friction unit equals to the product of pressure
on line 500 and magnification factor.
During the starting of shifting, the used on/off solenoid valve is in opened status which cut off the oil loop supply from line 500
to piston.
At the same time, VPS pressure is decreased to starting pressure valve, pressure set by regulating valve and pressure setting
value required by execution of VPS by pushing the piston from the valve. The shifting is finished through the on/off solenoid
valve, VPS returns to the waiting status
Pointed to each gear-position, the system can make the brake belt; clutch or both realize
the electronic control.
Mode indicator lamp: the mode indicator lamp can be used to indicate the current selected and whether the overpeed status
exists. The mode indicator lamp is located in instrument panel generally. (Refer to Part 2.3)