2006 GREAT WALL HOVER oil pressure

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

Caution: When maintaining the fuel supply system, if the oil
path needs to be removed, the pressure of the fuel system must
be released to avoid the ejection of high pressure fuel.
Disassembly of the fuel tank
1. First remove the oil-in and oil return hard tube of the
generator, the oil return hard tube of fuel tank, and the
connection rubber tube between the back parts of hard vaporizer
tube. Release the pressure of oil path system slowly, block the
joints with cotton cloth, lest there is ejection of high pressure
oil.
2. Remove the oil filling port at the back of the fuel tank and the
clip of the connection rubber tube of ventilation tube, there are
two clips altogether.
3. Remove the bolts fixing the fuel tank, there are 6 bolts
altogether;
4. Remove the oil-in and oil-out tube from the fuel tank, remove
the vaporizer tube joints and line bundle connector;

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)

Automatic transmission-17
Figure 3.10 1-2 gear shift valve
Clutch combination regulating valve (refer to Figure 3.15) is a constant ratio regulating valve which provide the regulating pressure
of clutch C1 to control the change ratio of shifting quality clutch status. The ratio is about 2.25:1.
When the S3 is opened, the oil of 3
rd-Gear is provided to the valve and adjust the pressure (CAF) to 2.25 times of S5 signal
pressure. When S3 is in closed status, the output pressure is 2.25 times of pressure of line 500.
9. Clutch combination regulating valve

Automatic transmission-20
Figure 3.17 reverse lock valve
12. Primary regulating valve
Primary regulating valve (PRV) (refer to Figure 3.18) can regulate the line pressure of transmission (or pump output
pressure). The valve can give the high or low line pressure according to the on/off status of S6. When S6 is in on or off status,
the pressure S6 is applied on PRV, move it and has the action of spring force. Open the line pressure loop to turn on the inlet
of pump to reduce the line pressure. Generally, the line pressure is small when the throttle position is opened lightly and in
patrol status. It will cause the closing of S6 when the opening degree of throttle position is large and because the high line
pressure valve
For all shifting pressures are controlled by output of separation brake belt , clutch regulating valve and S5, so all step control
of line pressure has not affect on effect of shifting sensing.
By the oil inlet of torque converter, PRV also adjust the oil supply of hydraulic torque converter. The level effect of PRV
should ensure the priority of valve, i.e. it can keep the line pressure in low engine speed condition. When the speed of engine
is increased and the pump supplies excess oil, the PRV acts to open the torque converter oil inlet cover to increase the pressure
of torque converter. If the oil amount is beyond the requirement of transmission, PRV will act further to allow the oil return
to the suction inlet.
Figure 3.18 Primary regulating valve
Figure 3.19 Torque converter on/off regulating valve
The torque converter regulating valve (refer to Figure 3.19) adjusts the pressure applied on torque converter clutch oil.
According to the signal pressure form loop S5, adjust the oil flow status from line pressure loop in valve. With the change of
pressure signal of loop S5, the engagement and disengagement of torque converter clutch can be finished by electric control.
13. Torque converter on/off regulating valve

Automatic transmission-26
Power transmission
Introduction
It has the following power transmission pointed to different Gear-position:
power transmission N-Gear and P-Gear
power transmission R-Gear
power transmission manual 1
power transmission Automatic 1st-Gear
power transmission Automatic 2nd -Gear
power transmission Automatic 3rd -Gear
power transmission Automatic 3rd-Gear locking
power transmission Automatic 4th -Gear (overspeed -gear)
power transmission Automatic 4th -Gear locking
For description of each kind of power transmission condition, refer to following parts.
Table 5.1 describe the on-off condition of each unit in all gear condition.
Name of participated unit
Position C1 C2 C3 C4 B1 B2 1-2
OWC 3-4
OWC LU
clutch
Parking and neutral position － － － － － X － － －
Reverse － － X － X － － －
Manual 1st -G ear － X － X － X － X
Automatic 1st- Gear － X － － － － X －
Auto 2nd-Gear and manual
2nd -G ear － X － X X － － X － Automatic 3rd –Gear and
manual 3rd-Gear X X － X － － － X － Automatic 3rd-Gear locking
and manual 3rd-Gear
locking X X － X － － － X X
Automatic 4th -Gear
(overspeed -gear) X X － － X － － － －
Automatic 4th -Gear locking
X X － － X － － － X
In P-Gear or N-Gear, the planetary gear assembly has not the drive. The rear brake belt is used to eliminate the voice generated in
engagement with reverse gear and increase the application of 4WD. It is without the engagement of clutch and brake belt.
In parking-Gear, the locking of mechanism is realized through the engagement of brake lever installed on housing and tooth of
output shaft gear ring.
Control
In stabl
e status, to maintain the arrangement, the status of solenoid valve and valve is shown as follows:
solenoid valve S1 and S2 is powered off.
The line (pump) pressure is applied on the primary regulating valve (PRV) and electromagnetic supply valve.
The torque converter, oil cooler and lubrication loop are filled up with the transmission fluid from the primary regulating
valve.
The line pressure 500 loop is filled up with the transmission fluid from the electromagnetic supply valve.

S5 will be filled up with the transmission fluid through the variable pressure

egulating valve (S5) .
The line pressure is prohibited form entering into the drive loop through the manual-operated valve .
B1 loop and all clutch loop are opened to drainage port.