brake GREAT WALL HOVER 2006 Service User Guide

Automatic transmission-11
Diagnosis input
solenoid valve
1and 2 S1 and S2 is the normal open solenoid valve, which is used to set the gear-position with other switch
solenoid valve. It determines the static gear-position by operating the gear shift valve. Refer to Table 3.5,
S1 and S2 also send the pressure single to allow or prohibit the engagement with rear brake belt.
solenoid valve
3and 4 S3 and S4 are the normal-opened solenoid valve which is used to control the shifting quality and sequence in
combination. S3 control the open or close of the clutch. S4 is used to control the on and off of the front brake
belt regulating valve.
solenoid valve 5 S5 is the variable pressure solenoid valve which can release the pressure of gear-position shifting. It provides
the pressure signal to the clutch and brake belt regulator and controls the shifting pressure. S5 also provides
the pressure single to the torque converter clutch regulating valve.
solenoid valve 6 S6 is the normal-opened solenoid valve, which is used to the set the H/L level of pipeline pressure. The
pipeline pressure is high when the solenoid valve is closed.
solenoid valve 7 S7 is the normal-opened solenoid valve which is used to control the engagement status of torque converter
licking clutch. It makes the clutch to generate the action when the S7 is in opened status.
Table 3.4 Status and function of solenoid valve

Gear-position S1 S2
1st-Gear On On
2nd-Gear Off On
3rd-Gear Off Off
4th-Gear On Off
R-Gear One of them is in On position
at least.
N-Gear Off Off
P-Gear Off Off
Table 3.5 Logic status of solenoid valve in static gear-position

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-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-16
Figure 3.9 manual-operated valve 3.
1-2 shift valve (refer to Figure 3.10) has two position status. It must be in the position (2, 3, 4) for the convenience of raising
gear in 1
st-Gear. It is using for all 1-2 and 2-1 shift.
Through the power supply of S1 and (or ) S2, the 1-2 shift valve can acquire its On/Off status.
During 1-2 shift period, drive the transmission fluid from manual-operated valve to the 2
nd-Gear loop. During the shifting form
2 to 1, the brake belt is engaged and drain the oil through the 1-2 Gear shift valve.
When in 1
st-gear position, the 1-2 gear shift valve operates with the 3-4gear shift valve (described as follows) combinedly to
separate the clutch C4; if in 2
nd-Gear position, engage the clutch C4. When select the manual Gear-1, the clutch C4 engages with
the rear brake belt (B2).
31-2 shift valve

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

Automatic transmission-22
Power transmission system
The power transmission system includes:
Torque converter equipped with single lock clutch.
4 multi-plate clutch assemblies
2 brake belts
2 one-way clutches
Planetary gear assembly
parking mechanism
A traditional planetary gear assembly composed by six pinions is used in four-speed transmission. It realizes the 4 Gear power
transmission through the drive gear bracket.
So, the cross arrangement is the main arranging method. In the box, there are four subassemblies, shown as follows:
Gear bank central support
C1-C2-C3-clutch C4 subassembly
Pump assembly
Valve assembly
One piece or one set of optional shim is located between the input shaft flange and center of stator support shaft axle of and used
to control the end flotation of transmission. The structure arrangement allows the inspection for the subassembly during the
product manufacturing period.
For description of power transmission system refer to table 4.1 and Figure 4.1:
When the clutch C2 is engaged and 1-2 one-way clutch is engaged, the gear is in 2nd-Gear at this time. During the 1-2 shifting
process, B1 brake belt is combined and the 1-2 one-way clutch is separated (OWC). During the 2-3 shifting period, the clutch
C1 is engaged and the B1brake belt is released. During the 3-4 shifting period, B1brake belt is engaged and 3-4 one-way clutch
is released. For reverse gear, the clutch C3 and B2brake belt is engaged.
When the gear position is in manual 1st, 2
nd and 3rd gear position, the engagement of the clutch C4 can provide the brake of
engine. Additionally, in the drive scope of 2
nd and 3rd Gear, the engagement of clutch C4 can eliminate the unfavorable freewheel
inertia. In the scope of manual 1
st-Gear, the low speed shifting is realized by the engagement of B2brake belt.
The front and rear servo has the figure surface design which requires the accurate friction and need not the secondary regulating
valve. When use the transmission fluid with new static factor, the design of the friction unit can meet the requirement that need
low shifting energy and high static holding force. The transmission uses the non-asbestos friction material.
LUGear position Gear ratio
1st-Gear 2.393
2
nd-Gear 1.450
3
rd-Gear 1.000
4
th-Gear 0.677
R-Gear 2.093
Manual 1 2.393
C3C4 B1 B2
Name of participated unit
* For operation of specified vehicle refer to user’operation manual.
LU: hydraulic torque converter lock clutch
Table 4.1 Participated unit and gear ratio in different gear position

Automatic transmission-23
Figure 4.1 Power flow chart
Torque converter
The torque converter (refer to Figure 4.2) consists of the turbine, stator, impeller and a lock throttle brake and piston assembly.
Same as that of the traditional torque converter, the impeller is connected to the end cover of the torque converter. The turbine is
connected to the input shaft through the spline. The stator is installed on the pump housing through the one-way clutch .
Figure 4.2 Section of torque converter
The buffer and piston assembly can make the torque converter is locked in proper condition. The locking action only occurs
in the condition of specified throttle position opening and vehicle speed. When the hydraulic force makes the buffer and piston
assembly is coupled on the cover of torque converter, it can acquire the locking status. In this status, it can eliminate the
unnecessary sliding. It can increase the economical efficiency of fuel oil when the locking action is generated. When in locking
status, the torque buffer spring in the buffer and piston can absorb the torque fluctuation of engine
.
Clutch assembly
It has four types of clutch assembly (refer to Figure 4.3). All clutch assemblies are composed of several layers of steel plate and
friction disk.
Clutch C1 When it is engaged, the drive shaft drive the planet carrier. The condition occurs in 3
rd and 4th Gear.
Clutch C2 When it is engaged, the drive shaft drive the forward central gear through the 3-4 one-way clutch. The conditio
occurs in 1
st, 2nd and 3rd-Gear condition.
Clutch C3 When it is engaged, the drive shaft drive the backward central gear. The condition occurs in R-Gear position.
Clutch C4 It can provide the brake of engine during overspeed when is engaged, The condition occurs in manual 1
st, 2nd and 3rd
–Gear, also in automatic 2nd and 3rd-Gear to avoid the unfavorable inertia rotation of freewheel.

Automatic transmission-24
Front servo and brake belt Rear servo and brake belt
Figure 4.4 brake belt
One-way clutch
The transmission has two one-way clutches, 1-2 one-way clutch and 3-4 one-way clutch (notice that the third one-way clutch is
located on torque converter, also called as retainer)
1-2 one-way clutch is located between the planet carrier assembly and central shaft. The structure makes the planet carrier only
can rotate in single direction around the central shaft. The one-way clutch is only engaged in automatic 1
st-Gear.
3-4 one-way clutch is located between the clutch C4 and clutch C2.The structure makes the clutch C2 drive the front planetary
gear in 1
st, 2nd and 3rd –Gear, but is disengaged in 4th-Gear and overspeed.
Planetary gear assembly
The planetary gear block used in transmission is the traditional lavena gear block consisted of6 pinions.
Parking mechanism
When select the parking-Gear, the steering column will move the parking lever backwardly to engage with the parking ratch
(refer to Figure 4.5). The ratchet is engaged with the tooth of external gear ring fear to lock the output shaft axle in the
transmission. When it is not in parking-gear, the return spring will release the parking ratchet and unlock the output shaft to
prevent the occurrence of accident parking action.
Figure 4.3 Clutch assembly
Brake belt
The transmission has two brake belts, brake belt B1 (named as 2-4 brake belt sometimes ) and brake belt B2 (named as low-speed
– reverse gear brake belt ) refer to Figure 4.4.
The brake belt B1 is a flexible brake belt which is engaged with front servo piston. When it is in 2
nd and 4th –Gear, the brake belt
B1 starts to act. When the brake belt acts, it can prevent the rotation of reverse central gear by maintaining the clutch C3 assembly
is in static. In 2
nd –Gear, only the external surface of piston is used. In 4thGear, both sides are used to acquire more clamping force.
The brake belt B2 is a solid brake belt which is meshed with the rear servo piston. When the B2 acts, it prevents the rotation of
planet carrier assembly. When in manual 1
st-Gear, only the external surface of piston is used. In reverse-Gear, both sides are used
to acquire more clamping force.

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.