Powertrain

POWER TRAIN DESCRIPTION





COMPONENT DESCRIPTIONS





NOTE:
- All directions of rotation are viewed from the oil pump.


FORWARD CLUTCH
- When hydraulic pressure acts upon the clutch piston, the drive plates and the driven plates are pressed tightly together, and the rotation of the turbine shaft is transmitted, via the reverse and forward drum and one-way clutch 1, to the small sun gear.

COASTING CLUTCH
- When hydraulic pressure acts on the clutch piston, the drive plates and the driven plates are pressed tightly together, and the rotation of the turbine shaft is transmitted, via the reverse and forward drum, coasting clutch drum and one-way clutch inner race, to the small sun gear.
- Then when the coasting clutch engages, the forward clutch is engaged, with the result the one-way clutch 1 becomes locked.





- The return spring is common for the forward clutch and the coasting clutch.


3-4 CLUTCH
When hydraulic pressure acts on the clutch piston, the drive plates and the driven plates are pressed tightly together, and the rotation of the turbine shaft is transmitted, via the 3-4 clutch drum and the carrier hub, to the planetary carrier.

REVERSE CLUTCH





- When hydraulic pressure acts on the clutch piston, the drive plates and the driven plates are pressed tightly together, and the rotation of the turbine shaft is transmitted, via the reverse and forward drum and the 2-4 brake drum, to the large sun gear. A diaphragm spring is used for return spring.


2-4 BRAKE
- When hydraulic pressure is applied between the servo retainer and the servo piston (brake band engagement side), the servo piston overcomes the spring force and acts on the brake band, thus locking the 2-4 brake drum.
- When hydraulic pressure is applied between the servo piston and the transaxle case (brake band disengage side), the servo piston is pressed toward the servo retainer side. The brake band expands by its own spring force, thus releasing the 2-4 brake drum.
- When hydraulic pressure is applied simultaneously between the servo retainer and the servo piston and between the servo piston and transaxle case, the servo piston is pressed to the servo retainer side as a result of the difference of the surface area between the two, thus releasing the 2-4 brake drum.

LOW AND REVERSE BRAKE





- When hydraulic pressure acts on the brake piston, the drive plates and the driven plates are pressed tightly together, and the transaxle case and the low and reverse brake inner race are connected. The rotation of the planetary carrier is locked when the low and reverse brake is activated.


ONE-WAY CLUTCH 1
- If the rotation speed of the one-way clutch outer race is faster than that of the one-way clutch inner race, the sprags enter between the two races and lock them. Consequently, the driving force is transferred to the small sun gear via one-way clutch 1. During in 4GR, one-way clutch 1 runs idle and does not transfer the driving force because the rotation speed of the one-way clutch inner race is faster.

ONE-WAY CLUTCH 2





- The one-way clutch inner race rotates counterclockwise freely. However, in the roller type, if the inner race tries to rotate clockwise, the rollers move to the shallower grooves and enter between the races. In either case, the one-way clutch inner race is locked. In other words, one-way clutch 2 locks the clockwise rotation of the planetary carrier, the pinion gear.

PARKING MECHANISM
- When the gear selector is moved to P position, the parking pawl engages the parking gear of the output shell, locking the output gear (to drive wheels).

CONSTRUCTION
- The parking pawl engages the parking gear via the parking pawl shaft only in P position. It is held away from the, parking gear in all other positions and ranges by the return spring.
- The parking rod slides on the top of the actuator support and is connected to the manual plate via the parking assist lever.

OPERATION





- When the selector lever is moved to P position, the manual shaft and manual plate, move the parking rod, via the parking assist lever, in the direction of the arrow. The cam pushes the parking upward and the parking pawl engages the parking gear.