SsangYong Musso. Manual - part 465

AUTOMATIC TRANSMISSION  5A-37

Figure 3.16 - Clutch Apply Regulator Valve

Clutch Apply Regulator Valve

The clutch apply regulator valve (refer figure 3.16) is a fixed ratio valve. This valve provides a regulated pressure to
the C1 clutch and controls the rate of change of state of the clutch to give the desired shift quality.

This ratio is 2.25 : 1.

Third gear oil supplied to the valve is regulated to provide an output pressure (CAF) of 2.25 times the S5 signal
pressure when S3 is On. When S3 is Off the output pressure is 2.25 times the line 500 pressure.

Band Apply regulator Valve

The band apply regulator valve (refer figure 3.17) is a fixed ratio valve. It provides a regulated pressure to the front
servo, and controls the rate of change of state of the front band (B1) to give the desired shift quality.

This ratio is 1.4 : 1.

Second gear oil supplied to the valve is regulated to provide an output pressure (BAF) of 1.4 times the S5 signal
pressure when S4 is On. When S4 is Off the output pressure is 1.4 times the line 500 pressure.

Figure 3.17 - Band Apply Regulator Valve

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 the
forward 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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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 valve
contains 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-40  AUTOMATIC TRANSMISSION

Converter Clutch Regulator Valve

The converter clutch regulator valve (refer figure 3.20) regulates
the pressure of the oil which applies the converter clutch. Input
oil from the line 500 circuit is regulated within the valve, with
the output pressure being variable according to the signal
pressure from the S5 circuit. Converter clutch apply and release
application is smoothed by electronically varying the S5 circuit
pressure.

Converter Clutch Control Valve

The converter clutch control valve (refer figure 3.21) is a two position valve which applies or releases the converter
clutch.

The switching of this valve is governed by the signal pressure from S7.

When the valve is in the off or released position, converter feed oil from the PRV is directed to the release side of the
converter clutch. After flowing through the converter, oil returns to the converter clutch control valve and is then
directed to the oil cooler.

When the valve is in the on or applied position, regulated oil from the converter clutch regulator valve is directed to
the apply side of the converter clutch. This oil remains within the converter because the converter clutch piston is
sealed against the flat friction surface of the converter cover. To provide oil flow to the cooler the converter clutch
control valve directs converter feed oil from the PRV directly to the cooler circuit.

Figure 3.21- Converter Clutch Control Valve

Figure 3.20 - Converter Clutch Regulator Valve