2003 SSANGYONG MUSSO engine

AUTOMATIC TRANSMISSION 5A-39
Primary Regulator Valve
The primary regulator valve (PRV) (refer to figure 3.19) regulates the transmission line pressure (or pump output
pressure). This valve gives either high or low line pressure depending on whether S6 is switched Off or On, When S6
is switched On,S6 pressure is applied to the PRV moving it against spring pressure and opening the line pressure
circuit to the pump suction port resulting in reduced line pressure. Low line pressure is used during light throttle
applications and cruising. Heavy throttle will cause S6 to switch Off and thereby cause high line pressure.
This stepped line pressure control has no detrimental effect on shift feel because all shifting pressures are controlled
by separate band and clutch regulator valves, and the output of S5.
When reverse gear is selected, both the low and high line pressure values are boosted to guard against slippage.
This is achieved by applying reverse oil line pressure to the PRV to assist the spring load. The other end of the valvecontains ports for line pressure feedback and 56 pressure.
The PRV also regulates the supply of oil to the converter via the converter feed port. The cascade effect of the PRV
ensures the first priority of the valve is to maintain line pressure at very low engine speeds. When the engine speed
increases and the pump supplies an excess of oil the PRV moves to uncover the converter feed port thereby pressurising
the converter. If there is an excess of oil for the transmission’s needs then the PRV moves further to allow oil to return
to the suction port.
Figure 3.19 - Primary Regulator Valve

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

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

5A-52 AUTOMATIC TRANSMISSION POWER FLOW - DRIVE 2 AND MANUAL 2
In Drive 2 and Manual 2, transmission drive is via the input shaft and forward clutch cylinder. The elements of the
transmission function as follows :
The C2 clutch is applied 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 B1 band is applied holding the reverse sun gear stationary therefore the long pinion ‘walks’ around the
reverse sun gear taking the internal ring gear and output shaft with it in a clockwise or forward direction.
The C4 clutch is applied to bypass the 3-4 OWC and provide engine braking on overrun.
Control
To maintain this arrangement in the steady state solenoids and valves are activated as follows: Solenoid S1 is switched Off. S2 is switched On. Solonoid S1 is switched Off. S2 is switched On.
Drive (line pressure) oil from the manual valve engages the C2 clutch.
When S1 switches off , S1 oil pressure, which is derived from line 500 pressure, moves the 3-4 shift valve to
the left. At the same time S1 oil is directed to the 1-2 shift valve which moves the valve to the second gear position.
2nd oil (line pressure) from the 1-2 shift valve is directed to the band apply regulator valve, and to the 2-3 shift
valve.
The band apply regulator valve supplies 2nd oil (regulated to line pressure multiplied by the valve ratio) to the
band apply feed (BAF) circuit.
Band apply feed oil is directed to:
- The outer apply area of the front servo- The 1-2 shift valve to provide an exhaust port when the transmission is shifted to first gear - The 3-4 shift valve for use when the transmission is shifted into fourth gear
Drive (line pressure) is routed through the 3-4 shift valve to apply the C4 clutch.
Refer to figure 5.5 and table 5.6.
Table 5.6 - Engaged Elements - Drive 2 and Manual 2
Gear State
Drive 2 and Manual 2 C1
- C2
X C3
- C4
X B1
X B2
- 1-2
OWC - 3-4
OWC X LU
CLUTCH -
ELEMENTS ENGAGED

5A-54 AUTOMATIC TRANSMISSION POWER FLOW - DRIVE 3 AND MANUAL 3
In Drive 3 and Manual 3, 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 C1 clutch is engaged to drive the planet carrier.
The forward sun gear and the planet carrier are driven clockwise at the same speed therefore there is no
relative motion between the sun gear and the pinions.
The ring gear and output shaft are driven in a clockwise or forward direction at input shaft speed.
The C4 clutch is applied to bypass the 3-4 OWC and provide engine braking on overrun.
Control
To maintain this arrangement in the steady state solenoids and valves are activated as follows: Solenoid S1 is switched Off. S2 is switched Off.
With S1 and S2 switched Off, the 2-3 and 3-4 shift valves are held in the third gear position by line 500
pressure.
The 1-2 shift valve is held in the third gear position by S1-S2 oil pressure.
2nd oil (line pressure) from the 1-2 shift valve is directed to the band apply regulator valve. and to the 2-3 shift
valve.
The band apply regulator valve supplies 2nd oil (regulated to line pressure multiplied by the valve ratio) to the
band apply feed (BAF) circuit.
Band apply feed oil is directed to:
- The outer apply area of the front servo
- The 1-2 shift valve to provide an exhaust port when the transmission is shifted to first gear
- The 3-4 shift valve for use when the transmission is shifted into fourth gear
2nd oil at the 2-3 shift valve is directed to the 3rd oil circuit.
3rd oil from the 2-3 shift valve is directed to the clutch apply regulator valve, and to the 4-3 Sequence Valve.
The clutch apply regulator valve supplies oil (regulated to line 500 pressure multiplied by the valve ratio) to the
clutch apply feed (CAF) circuit.
The CAF oil is directed to:
- The C1 clutch- The C1 bias valve- The 4-3 sequence valve
At the 4-3 sequence valve the CAF oil becomes band 1 release feed (B1R-F) oil, and is directed through the
3-4 shift valve to the spring end of the 4-3 sequence valve, and to the release side of the front servo piston to hold band 1 off.
Drive (line pressure) is routed through the 3-4 shift valve to apply the C4 clutch.
Refer to figure 5.6 and table 5.7.
Table 5.7 - Engaged Elements - Drive 3 and Manual 3
Gear State
Drive 3 and Manual 3 C1
X C2
X C3
- C4
X B1
- B2
- 1-2
OWC - 3-4
OWC X LU
CLUTCH -
ELEMENTS ENGAGED