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