2006 GREAT WALL HOVER lock

Transmission-35
Disassembly of rear output shaft assembly
a. Use the special tools to remove the lock nut
Caution: The tightening torque is 87-120N
m when in-
stall the lock nut.
b. Remove the ball bearing
Rear output shaft assembly
cRemove the oil guide plate
circlips for shafthigh and low
gear sleeve
needle bearing
high and low gear hub
needle bearing
low-speed driven gear
rear output shaft
ball bearing
spacing platesecond/ fourth drive gear hub
second/fourth
drive geared sleeve
sprocket needle bearing bushing
needle
bearing
drive sprocket
spacer of
drive sprocket
oil guide plate assembly
ball bearing
assembly
87-120
N m: specified torque
Used component which can not be used any more.
Use the special tools
dRemove the spacing ring

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-5
Table 2.1 Gear selection and its function
Gear selection function
1st-Gear
(manual 1
st-Gear ) The first gear is using for climbing and braking. It is a function which limits the speed of
the car. The speed limitation by engine is realized by reduce the opening degree of
throttle position.
2nd-Gear (automatic, manual
2
nd-Gear) In economic mode, it can process the 1
st and 2nd shifting operation when engage the 2nd
–Gear. The limitation of vehicle speed by engine is realized through reducing the
opening of throttle position. in 4WD 4 high, , the transmission will maintain 2
nd-Gear
position The manual mode and winter-Mode will only maintain 2nd-Gear 。
3rd-Gear
(automatic, manual 3rd-Gea) In economic mode and dynamic mode, it can process the shifting operation of 1
st, 2nd
and 3rd-Gear when engage the 3rd-Gear, and can reaches the very high vehicle speed. At
this time the locking clutch can process the locking action, refer to vehicle user manual.
The limitation of vehicle speed by engine is realized by reduce the opening of throttle
position. In 4WD 4 low, the transmission should be maintained in 3
rd –Gear position.
Under manual mode, the transmission will be kept in 3rd-Gear.
D-gear
(drive) It can process the 1
st, 2nd, 3rd and 4th –Gear position operation and gear-shifting operation
of (1-2), (1-3), (2-3), (2-4), (3-4), (4-3), (4-2), (3-1) and (2-1). This shifting operation is
processed by taking the vehicle speed, throttle position, throttle position switching
frequency (or forced Gear-decreasing) as the parameter. The locking clutch can process
the locking action in 3rd –Gear, 4
th-Gear according to the type of vehicle. Refer to user
manual of vehicle.
N-Gear
(neutral gear) Only the rear brake belt is engaged at this time. It determines whether the function can
be realized according to the vehicle speed, engine speed and throttle position. But the
gear-position sensor allows the starting of engine. Allow the slide of N-Gear.
R-Gear
(reverse gear) Set the anti-misoperation in forward function according to the vehicle speed, engine
speed and throttle position opening to realize the reverse operation. The gear-position
sensor can start the revers e lamp.
P-gear
(parking gear) Only the rear brake belt is engaged at this time. The function can be determined
according to the vehicle speed, engine speed and throttle position. The output shaft of
transmission is locked. The gear-position sensor can start the engine.

Automatic transmission-7
Indicator lamp
Figure 2.2
control system
General
The transmission has two sets of control system, a electric control system and a hydraulic control system. The electric control
system monitors the vehicle parameter and adjusts the transmission performance; the hydraulic control system executes the
command of electric control system.
Electric control system
The electric control system consists of the sensor, TCU and 7 solenoid valves. TCU read in the data and make the output under the
control of software based on the value stored in Read Only Memory (ROM).
TCU controls the hydraulic control system and the control is realized through the valve and pump assembly. The system includes
7 solenoid valves, in which 6 valves are used to control the line pressure, operate the shift valve and hydraulic torque converter lock
clutch and switch on and off two regulating valves (Two regulating valves control the shift feel). The seventh solenoid valve is the
pressure regulating solenoid valve (VPS) which controls the shift feel with other three regulating valves. Figure 3.1 is the typical TCU
control system plan.
The figure includes all elements of electric control system involved in the section.
throttle position
open sensor
Engine speed
vehicle speed
Transmission
fluid temperature
mode selection
(instrument panel
/console )
Gear sensor
Forced step-
decreasingK line
shifting
logic
shifting
sensing
line
pressurehydraulic
control
system
Solenoid valve 1
Solenoid valve 2
Solenoid valve 3
Solenoid valve 4
Solenoid valve 5
Solenoid valve 6
Solenoid valve 7
pressure regulating
solenoid valve
Mode indicator lamp
Gear indicator lamp
set and other
necessary equipment
indication

Automatic transmission-14
The main box includes:
z BIR blow-off valve
1. Valve
Figure 3.7 shows the valve unit in the view of transmission fluid tank. Figure 3.8 illustrates the pump cover.
2. Manual-operated valve
The manual-operated valve (refer to Figure 3.9) is connected to the car gear selection mechanism. It controls the transmission
fluid flow to the forward or reverse loop. Except in manual 1st-Gear position, the function of manual-operated valve is same
in all forward gear. In manual 1st-Gear, the transmission fluid will enter into the shift valve 1
2 to make the rear brake belt
and C4 overspeed gear clutch is engaged respectively. The hydraulic control system is located in the valve, pump and main box.
The valve includes the following types:
zManual-operated valve
z Three shift valves
zsequence valve
z electromagnetic pressure control valve
zline pressure control valve
zclutch connection regulating valve
zbrake belt connection regulating valve
zsolenoid valve 1 to solenoid valve 6
zreverse lock valve
The pump includes the following types:
zprimary regulating valve (control line pressure)
ztorque converter clutch regulating valve
ztorque converter clutch control valve
z
solenoid valve 7 Hydraulic control system

Automatic transmission-19
Figure 3.15 clutch combination regulating valve
10. Brake belt combination regulating valve
aP-Gear or N-Gear, vehicle speed 3km/h
b
R-Gear , speed 10km/h
c
Speed of engine : 1250rpm
d
Diesel vehicle , Opening degree of throttle position: 25
eGasoline vehicle, opening degree of throttle position: 12
In this condition, the TCU control solenoid valve S1 and S2 are closed. The reverse lock valve is affected by the pressure form
S1-S2 transmission fluid; connect the line pressure to loop B2. The transmission fluid flows to servo internal and external
attachment area, the B2 is engaged.
When none of above condition is met, TCU control the solenoid valve S1 and S2 to be opened. The pressure of S1-S2 is
released and the spring control valve body is in locking status at the same. In this condition, the B2 attachment is prohibited.
The feature can realize the protection for transmission by controlling the B2 in high speed and providing the reverse-gear
locking.
If the transmission is in failure mode, then the rear brake belt will be attached in P-Gear, R-Gear and N-Gear.
Figure 3.16 brake belt 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