SSANGYONG MUSSO 2003 Service Manual

5A-42 AUTOMATIC TRANSMISSIONPOWER TRAIN SYSTEM
The Power Train System consists of: A torque converter with single face lock-up clutch
Four multi-plate clutch assemblies
Two brake bands
Two one-way clutches
Planetary gearset
Parking mechanism
A conventional six pinion Ravigneaux compound planetary gearset is used with overdrive (fourth gear) being obtained
by driving the carrier.
The cross-sectional arrangement is very modular in nature. Four main sub-assemblies are installed within the case
to complete the build. These sub-assemblies are: Gearset-sprag-centre support
C1 -C2-C3-C4 clutch sub-assembly
Pump assembly
Valve body assembly
One, or a combination of selective washers are used between the input shaft flange and the number 4 bearing to
control the transmission end float. This arrangement allows for extensive subassembly testing and simplistic finalassembly during production.
A general description of the operation of the Power Train System is detailed below. Refer to table 4.1 and figure 4.1.
First gear is engaged by applying the C2 clutch and locking the 1-2 One Way Clutch (1-2 OWC). The 1-2 shift is
accomplished by applying the B1 band and overrunning the 1-2 OWC. The 2-3 shift is accomplished by applying the
C1 clutch and releasing the B1 band. The 3-4 shift is accomplished by re-applying the B1 band and overrunning the
3-4 OWC. Reverse gear is engaged by applying the C3 clutch and the B2 band.
The C4 clutch is applied in the Manual 1,2 and 3 ranges to provide engine braking. In addition, the C4 clutch is also
applied in the Drive range for second and third gears to eliminate objectionable freewheel coasting. The B2 band is
also applied in the Manual 1 range to accomplish the low-overrun shift.
Both the front and rear servos are dual area designs to allow accurate friction element matching without the need for
secondary regulator valves. All the friction elements have been designed to provide low shift energies and high static
capacities when used with the new low static co-efficient transmission fluids. Non-asbestos friction materials are used throughout.
Gear
First
Second ThirdFourth
Reverse
Manual 1 Gear
Ratio 2.741 1.508 1.0000.7082.4282.741 C1
XX C2
X X XX X C3
X C4
X X B1
X X X B2
X X 1-2
OWC X 3-4
OWC X XX LU
CLUTCH
X*X
ELEMENTS ENGAGED
* For Certain Vehicle Applications, Refer to the Owner's Manual.
Table 4.1 - Engaged Elements vs Gear Ratios

AUTOMATIC TRANSMISSION 5A-43
Figure 4.1 - Power Flow Diagram TORQUE CONVERTER
The torque converter (refer figure 4.2) consists of a turbine,
stator pump, impeller and a lock-up damper and piston
assembly. As in conventional torque converters, the impeller is
attached to the converter cover, the turbine is splined to the
input shaft and the stator is mounted on the pump housing via
a one way clutch (sprag).
The addition of the damper and piston assembly enables the
torque converter to ‘lock-up’ under favourable conditions. Lock-
up is only permitted to occur in third and fourth gears under
specified throttle and road speed conditions.
Lock-up is achieved by applying hydraulic pressure to the
damper and piston assembly which couples the turbine to the
converter cover, locking-up the converter and eliminating
unwanted slippage. Whenever lock-up occurs, improved fuel
consumption is achieved. Torsional damper springs are
provided in the damper and piston assembly to absorb anyengine torque fluctuations during lock-up. Figure 4.2 - Torque Converter Cross Section

5A-44 AUTOMATIC TRANSMISSION CLUTCH PACKS
There are four clutch packs (refer to figure 4.3). All clutch packs are composed of multiple steel and friction plates. C1 CLUTCHWhen applied, this clutch pack allows the input shaft to drive the planet carrier.
This occurs in third and fourth gears.C2 CLUTCH When applied this clutch pack allows the input shaft to drive the forward sun gear via the 3-4 OWC.
This occurs in all forward gears.C3 CLUTCH When applied this clutch pack allows the input shaft to drive the reverse sun gear. This only occurs in
reverse gear.C4 CLUTCH When applied this clutch provides engine braking on overrun. This occurs in Manual 1, 2 and 3 and
also Drive 2 and Drive 3 to prevent objectionable free wheel coasting.
Figure 4.3 - Clutch Packs

AUTOMATIC TRANSMISSION 5A-45
BANDS
The transmission utilises two bands, the B1 band (sometimes known as the 24 band), and the B2 band (sometimes
known as the low-reverse band). Refer to figure 4.4.
The B1 band is a flexible band which is engaged by the front servo piston. B1 is activated in second and fourth gear.
When activated B1 prevents the reverse sun gear from rotating by holding the C3 clutch assembly stationary. In
second gear only the outer area of the apply piston is utilised. In fourth gear both areas are utilised for greater clamping force.
The B2 band is a solid band which is engaged by the rear servo piston. B2 is activated in Park,
Reverse, Neutral and Manual 1. When activated B2 prevents the planet carrier assembly from rotating. In Manual 1
only the inner area of the apply piston is utilised. In Park, Reverse and Neutral, both areas are utilised for greater clamping force. Figure 4.4- Bands
ONE WAY CLUTCHES
The transmission uses two OWCs, the 1-2 OWC and the 34 OWC. (Note that a third OWC is located in the torque
converter, also known as a sprag.)
The 1-2 OWC is located between the planetary carrier assembly and the centre support. This allows the carrier to
rotate around the centre support in one direction only. The one way clutch is engaged only in Drive 1.
The 3-4 OWC is located between the C4 and the C2 clutch assemblies. This allows the C2 clutch to drive the forward
sun gear in first, second and third gears but unlocks in fourth gear and during overrun.
PLANETARY GEAR SET
The planetary gear set used in the transmission is a conventional six pinion Ravigneaux compound gear set.

5A-46 AUTOMATIC TRANSMISSION PARKING MECHANISM
When Park is selected the manual lever extends the park rod rearwards to engage the parking pawl (refer to (figure
4.5). The pawl will engage the external teeth on the ring gear thus locking the output shaft to the transmission case.
When Park is not selected a return spring holds the parking pawl clear of the output shaft, preventing accidental engagement of Park.
Figure 4.5 - Park Rod and Cross Shaft

AUTOMATIC TRANSMISSION 5A-47
POWER FLOWS
INTRODUCTION
The power flows for the various transmission selections are listed below: Power Flow - Neutral and Park
Power Flow - Reverse
Power Flow - Manual 1
Power Flow - Drive 1
Power Flow - Drive 2
Power Flow - Drive 3
Power Flow - Drive 3 Lock Up
Power Flow - Drive 4 (Overdrive)
Power Flow - Drive4 Lock Up
Each power flow is described in the following sections.
Table 5.1 details the engaged elements versus the gear selected for all transmission selections.
Gear State
Park and Neutral Reverse Manual 1 Drive 1Drive 2 and Manual 2Drive 3 and Manual 3Drive 3 Lock Up and Manual 3 Lock Up Drive 4 OverdriveDrive 4 Lock Up C1
-- - --
XX X X C2
--
XXXX X X X C3
-
X - - -- - - - C4
--
X
-
XXX
-- B1
-- - -
X
- - - - B2
XXX- - -- - - 1-2
OWC - --
X
--- - - 3-4
OWC - -
XX X XX
- - LU
CLUTCH - --- - -
X
-
X
ELEMENTS ENGAGED
Figure 5.1 - Engaged Elements vs Gear Selected
Planetary Gear Set

5A-48 AUTOMATIC TRANSMISSION POWER FLOW - PARK AND NEUTRAL
In Park and Neutral, there is no drive to the planetary gear set. The rear band is applied to eliminate ‘clunk’ on
engagement of the reverse gear, and to improve the low range engagement for 4WD applications. No other clutches
or bands are applied.
In Park the transmission is mechanically locked by engaging a case mounted pawl with teeth on the output shaft ring
gear. Control
To maintain this arrangement in the steady state solenoids and valves are activated as follows:
Solenoids S1 and S2 are switched off.
Line (pump) pressure is applied to the primary regulator valve (PRV) and to the solenoid supply valve.
The converter, oil cooler, and lubrication circuits are charged from the primary regulator valve.
The line 500 circuit is charged by the solenoid supply valve.
The S5 circuit is charged by the variable pressure solenoid (S5).
Line pressure is prevented from entering the drive circuit by the manual valve.
The B1 circuit and all clutch circuits are open to exhaust.
Refer to figure 5.1 and table 5.2.
Table 5.2 - Engaged Elements - Park arid Neutral
Gear State
Park and Neutral C1
- C2
- C3
- C4
- B1
- B2
X 1-2
OWC - 3-4
OWC - LU
CLUTCH -
ELEMENTS ENGAGED

AUTOMATIC TRANSMISSION 5A-49
POWER FLOW - REVERSE
In Reverse, transmission drive is via the input shaft and the forward clutch cylinder to the hub of the C3 clutch. The
elements of the transmission function as follows : The C3 clutch is engaged and drives the reverse sun gear in a clock-wise direction.
The B2 band is engaged and holds the planetary gear carrier stationary causing the long pinion to rotate anti-
clockwise about its axis on the pinion shaft.
The long pinion drives the internal ring fear in the same direction.
The internal ring being splined to the output shaft drives it in an anti-clockwise or reverse direction.
Control
To maintain this arrangement in the steady state solenoids and valves are activated as follows: Solenoids S1 and S2 are switched off.
Line pressure is directed through the reverse lockout valve to both the inner and outer apply areas of the rear
servo piston for B2 band application.
Line pressure feeds the reverse oil circuit via the manual valve.
Reverse oil is routed from the manual valve to the C3 clutch.
Reverse oil is also applied to the spring end of the primary regulator valve to assist the spring and to boost theline pressure value.
All other clutch and band apply circuits are open to exhaust.
Refer to figure 5.2 and table 5.3
Table 5.3 - Engaged Elements - Reverse
Gear State
Reverse C1
- C2
- C3
X C4
- B1
- B2
X 1-2
OWC - 3-4
OWC - LU
CLUTCH -
ELEMENTS ENGAGED

5A-50 AUTOMATIC TRANSMISSION POWER FLOW - MANUAL 1 In Manual 1, transmission drive is via the input shaft
to the forward clutch cylinder. The elements of thetransmission function as follows : The C2 clutch is engaged to drive the forward sun gear, via the 3-4 OWC.
The B2 band is engaged to hold the planetary gear carrier stationary.
The forward sun gear drives the short pinion anti-clockwise.
The short pinion drives the long pinion clockwise.
The long pinion rotating about its axis drives the internal ring gear and the output shaft in a clockwise or
forward direction.
The C4 clutch provides engine braking through the 3-4 OWC on overrun.
Control
To maintain this arrangement in the steady state solenoids and valves are activated as follows: Solenoids S1 and S2 are switched ON.
The 1-2,2-3, and 34 shift valves are held in their first gear positions by line 500 pressure.
Drive (line pressure) oil from the manual valve engages the C2 clutch.
Lo-1st (line pressure) oil is routed through the 1-2 shift valve to the C4 clutch, and to the inner apply area of
the rear servo piston for B2 band application.
Refer to figure 5.3 and table 5.4.
Table 5.4 - Engaged Elements - Manual 1
Gear State
Manual 1 C1
- C2
X C3
- C4
X B1
- B2
X 1-2
OWC - 3-4
OWC X LU
CLUTCH -
ELEMENTS ENGAGED

AUTOMATIC TRANSMISSION 5A-51
POWER FLOW - DRIVE 1
In Drive 1, transmission drive is via the input shaft to the forward clutch cylinder. The elements of the transmission function as follows : The C2 clutch is engaged to drive the forward sun gear.
The forward sun gear drives the short pinion anti-clockwise.
The short pinion drives the long pinion clockwise.
The 1-2 OWC prevents the planetary gear carrier from rotating under reaction force and the long pinion
rotates on its axis driving the internal ring gear and output shaft in a clockwise or forward direction.
There is no engine braking on overrun.
Control
To maintain this arrangement in the steady state solenoids and valves are activated as follows: Solenoids S1 and S2 are switched On.
The 1-2, 2-3, and 3-4 shift valves are held in their first gear positions by line 500 pressure.
Drive (line pressure) oil from the manual valve engages the C2 clutch.
Refer to figure 5.4 and table 5.5
Table 5.5 - Engaged Elements - Drive 1
Gear State
Drive 1 C1
- C2
X C3
- C4
- B1
- B2
- 1-2
OWC X 3-4
OWC X LU
CLUTCH -
ELEMENTS ENGAGED