Great Wall Hover. Service Manual - part 5

Transmission-29

Transfer case assembly (one)

Transfer case assembly 

  transfer case

housing assembly

rear output

shaft assembly

transfer case cover

26-36

30-35

     

aluminum gasket 18

30-35

waved spring

high speed gear chain

    front output shaft assembly

15-20

  side cover plate

bush

thrust washer

needle bearing

needle bearing

spacing ring

 O-RING

rear intermediate shaft

high/low gear

duplicate gear

 thrust washer

lock plate

14-19

h i g h / l o w   g e a r

declutch shift shaft

 high/low gear shift fork assembly

2

nd

/4

th

 drive

 declutch shift shaft

pin 5

26

2

n d

/ 4

t h

  d r i v e

shifting block

interlocking
cylinder pin

 spacing ring

2

n d

/ 4

t h

  d r i v e

shift fork

cylindrical compression spring

spring base

 split retainer

     

aluminum

          gasket 18

N 

m:   specified torque

Used component which can not be used any more.

 Pregummed component

transfer case housing assembly

N 

m:   specified torque

Used component which can not be used any more.

dustproof seal
 guide bushing

oil seal 

transfer case housing

ball bearing

front output shaft

ball bearing

bowel patch

circlips for hole

rear input shaft

auxiliary gear

disk spring

circlips for shaft

spacing ring

duplicate ball bearing

circlips for

shaft

  oil seal

 

back plate

Transfer case assembly (three)

Disassembly of transfer case assembly

4.Remove the shouldered lock screw plug

Use the wrench to remove the  shouldered lock screw plug M16

1.5

12

Caution: The tightening torque is 26-36N

m when install the

shouldered lock screw plug M16

1.5

12.

5.Remove the upper and lower drive switch M12

1.25

Caution: When install the upper and lower drive switch M12

1.

25, the tightening torque is within 26-36N

m

6.Remove the 2nd/4th drive switch M14

1.25

Caution: When install the 2nd/4th drive switch M14

1.25, the

tightening torque is with in 26-36N

m

N 

m:   specified torque

Used component which can not be used any more.

Transmission-31

7.Remove the shouldered lock screw plug M14

1.5

10

Caution: When install the shouldered lock screw plug M14

1.5

10, the tightening torque is within 26-36N

m

8.Remove the shouldered lock screw plug

a. Use the wrench to remove the  shouldered lock screw plug M12

1.25

10

Caution: When install the shouldered lock screw plug M14

1.5

10, the tightening torque is within 26-36N

m

b.Takeout mushroom lock spring

c. Use the magnetic rod to take out the steel ball.

9.Remove the transfer case cover

a. Use the wrench to remove 12 connecting bolts M10

1.25

65

between the transfer case cover and tranafer case housing.

Caution: The tightening torque is 26-36N

m when install the

bolt M10

1.25

65.

c. Remove the high/low drive declutch shift shaft elastic cylindrical pin

d. Remove the 2

nd

/4

th

 declutch shift shaft elastic cylindrical pin

e. Use the circlip pliers to remove the bearing snap ring

f. Use the rubber hammer to knock out the transfer case cover assembly

slightly and remove the transfer case cover assembly.

b. Remove the select & shift seating elastic cylindrical pin

Transmission-33

10. Remove the high and low gear drive declutch shift shaft

11.Remove the second and fourth drive declutch shift shaft

12. Use the plastic hammer to knock out the rear output shaft

      assembly, front output shaft assembly and chain out slightly

13. Remove the second/fourth shift block and high and low gear

      shift fork

14. Remove the housing of transfer case

a. Use the wrench to remove 4 bolts M10

1.25

35 and 2 nuts

M10

1.25 connected the gearbox and tranafer case housing

Caution: The tightening torque is 30

42 N•m when install

the connecting bolt of gearbox and housing of transfer case

b. Remove the housing of transfer case

15.Remove a location pin

For the disassembly of gearbox refer to “Disassembly of gearbox in

SC5M2D

C”

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

c

Remove the oil guide plate

circlips for shaft

high and low
 gear sleeve

needle bearing

high and low gear hub

  needle bearing

 low-speed driven gear

rear output shaft

ball bearing

 spacing plate

second/ 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

d

Remove the spacing ring

e. Use the magnetic rod to remove the steel ball.

f. Remove the drive sprocket and needle bearing

Caution: When install the drive sprocket, it should use the plug

gage to measure the drive sprocket axial clearance and ensure

within 0.19-0.338mm

g  Remove the drive geared sleeve

h. Use the magnetic rod to remove the steel ball.

i.  Dismantle the drive gear sleeve.

Transmission-37

j

Remove the gear hub

k

Remove the spacing plate

l. Use the circlip pliers to remove the circlip.

Caution: It should select the circlip for shaft according the angle

when install it.

m.Remove the high and low geared sleeve and gear hub

n. Remove the low-speed driven gear, needle bearing and rear output

shaft

Caution:  When install the low-speed driven gear, it should use the

plug gage to measure the axial clearance of low-speed driven gear

axial clearance to ensure the axial clearance is 0.17-0.284 mm

Mark

Thickness (mm)

White

Blue

Green

Automatic transmission-1

   Chapter 5

   Automatic transmission  (M88)

Instruction for automatic transmission .........................................2

Operation and display interface ..................................................5

Control system...........................................................................7

Power transmission system..........................................................22

Power transmission ...................................................................26

Diagnosis and test.......................................................................45

Adjustment................................................................................53

Disassembly /Assembly...............................................................55

Specification and special tools ...................................................90

Annex.........................................................................................92

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-3

8. Use two bolts to install the back device on the extended case of the transmission, these lengths are important. If it is too long,

it will hinder the end of the bolt and affect the threads on the case. Ensure the proper length and special torque of the bolt.

9. Pay attention that the height of the oil has been determined before delivery from the ION Company. The oil height needs not

checking or correction, except that improper oil is suspected to be used, or additional oil is needed because of leakage.

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

indication

gear 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 

1

st

-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 2

nd

 shifting operation when engage the 2

nd

 

–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  。 

3

rd

-Gear 

(automatic, manual 3rd-Gea) 

In economic mode and dynamic mode, it can process the shifting operation of 1

st

, 2

nd

 

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

, 2

nd

, 3

rd

 and 4

th

 –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 reverse 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-6

Selection of drive mode

The selection of drive mode includes a mode selection switch and indicator lamp. The drive mode selection switch is located

on the operating panel. It can provide the different mode selection according to the different type of car.

It has the optimal fuel economy when select the “normal” mode. At this time, the indicator lamp is not light. When select the

“dynamic” mode, the car will have the maximum dynamic performance and the “dynamic” mode indicator lamp is light. When select

the “snowland” mode, it will realize the starting of “2

nd

-Gear”, the “snowland” mode indicator lamp is light, meanwhile the

“dynamic” mode indicator lamp will be closed. When select the manual mode, press down the “snowland” switch firstly, the

“manual” light will be light when the gear is in 3, 2, 1. When in manual mode, 1-2, 2-3, 3-4, 3-2, 2-1, 1-3, 3-1 is shifted by driver

manually and can not be shifted automatically.  It can be used in car-racing etc. for the special mode of each model of car refers to

operation manual of user.

Operation    instruction

Function 

5 Brake 

function 

Can decrease the gear-position in slope to improve the brake effect and increase the vehicle safety. 

6 Speed-up 

function It can select the manual shifting to increase the vehicle speed completely during the speed-up. 

cautions 

7 

It must place the transmission in the P-Gear or N-Gear when start the engine. 

8 

It must place the transmission in P-Gear during the parking. 

9 

It must place the transmission in N-Gear when trail the car. 

10 

It must be powered off when remove the transmission. 

11 

It must be powered off when install the transmission. 

The transmission processes the communication and calculation with the engine electronic control computer by the precision 
central on-line computer. It not only save the fuel, but also provide the maximum mode function, including field, winter and 
manual selection. It provides the two conditions, manual and electric for the fast race of racing player. It has racing capacity which 
can compete the speed increasing with the manual transmission. 

automatic

Having anti-slide function

It is allowable that the D-Gear
in “W” mode is used in
snowland and M-A integration
mode.

automatic

automatic

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-

decreasing

K line

shifting
logic

shifting
sensing

line
pressure

hydraulic
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