solenoid SSANGYONG MUSSO 2003 Owner's Manual
[x] Cancel search | Manufacturer: SSANGYONG, Model Year: 2003, Model line: MUSSO, Model: SSANGYONG MUSSO 2003Pages: 1574, PDF Size: 26.41 MB
Page 897 of 1574

5A-38 AUTOMATIC TRANSMISSION
Reverse Lockout Valve
The reverse lockout valve (refer figure 3.18) is a two position valve contained in the upper valve body. This valve
uses 51-52 pressure as a signal pressure and controls the application of the rear band (B2).
While the manual valve is in D,3,2, or 1 positions, drive oil is applied to the spring end of the valve, overriding any
signal pressures and holding the valve in the lockout position. This prevents the application of B2 in any of theforward driving gears.
When the manual valve is in P, R or N positions, drive oil is exhausted and the reverse lockout valve may be toggled by S1-S2 pressure.B2 is applied in P, R, and N provided that the following conditions are satisfied:
1. In P or N, roadspeed 3 km/h.
2. In R, road speed 10 km/h.
3. Engine speed 1400 rpm.
4. For diesel vehicles, throttle 25%.
5. For gasoline vehicles, throttle 12%.
Under these conditions, the TCU switches solenoids S1 and S2 to Off. The reverse lockout valve toggles under the
influence of the S1-S2 pressure, to connect the line pressure to the B2 feed. Oil is fed to both the inner and outer
apply areas of the rear servo piston, applying B2.
If any of the above conditions are not satisfied, the TCU switches solenoids S1 and S2 to On. S1- S2 pressure is
exhausted and the valve is held in the lockout position by the spring. In this position, engagement of B2 is prohibited.
This feature protects the transmission from abuse by preventing the undesirable application of B2 at high speed, and
by providing a reverse lockout function.
Note that if the transmission is in failure mode, the rear band will be applied at all times in P, R and N.
Figure 3.18 - Reverse Lockout Valve <
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Page 907 of 1574

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
Page 908 of 1574

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