Band - 2-4
The 2-4 band locks the rear sun gear and drum to the transmission case. The 2-4 band encircles 2-4 band drum and small sun gear and operates during different conditions depending on the engine application. One end of the 2-4 band is secured to the anchor strut, the other end to the 2-4 band servo retainer.
Band - 2-4, Servo
When hydraulic pressure is applied between the 2-4 band servo retainer and the servo band piston, the servo band piston overcomes the spring force and causes the 2-4 band to lock 2-4 band drum and small sun gear.
When hydraulic pressure is applied between the servo band and the transmission case, the servo band piston is pressed toward the servo retainer side. This allows the 2-4 band to expand by its own spring force and release the rear sun gear and drum.
When hydraulic pressure is applied simultaneously between the servo band piston and 2-4 band piston retainer and the servo band piston and the transmission case, the servo band piston is pressed toward the servo retainer side due to the difference in surface area. The 2-4 band drum and small sun gear is released and rotates freely.
Clutches - Forward
When hydraulic pressure acts upon the forward clutch piston, the forward clutch disc pack is pressed tightly together, and the rotation of the turbine shaft is transmitted through the reverse clutch drum and one-way clutch to the primary sun gear.
Clutches - Coast
When hydraulic pressure acts on the coasting clutch piston, the coasting clutch disc pack is pressed tightly together, and the rotation of the turbine shaft is transmitted through the reverse clutch drum, the coasting clutch drum, and one-way clutch inner race, to the primary sun gear. With the coasting clutch engaged, the forward clutch is engaged, resulting in the one-way clutch becoming locked. Without the coasting clutch engaged, the one-way clutch will overrun during deceleration.
The return spring is common for the forward clutch and the coasting clutch.
Clutches - 3-4
When hydraulic pressure acts on the 3-4 clutch piston, the 3-4 clutch disc pack is pressed tightly together, and the rotation of the turbine shaft is transmitted through the 3-4 clutch cylinder and carrier hub to the front planet. The 3-4 clutch operates during third and fourth gear operation.
Clutches- Reverse
When hydraulic pressure acts on the reverse clutch piston, the reverse clutch disc pack is pressed tightly together, and the rotation of the turbine shaft is transmitted through the reverse clutch drum to the 2-4 band and small sun gear. The reverse clutch operates during reverse movement of the vehicle.
Direct Clutch and Reverse Clutch Operation
Band - 2-4, Servo
When hydraulic pressure is applied between the servo retainer and the servo piston (2-4 band engagement side), the servo piston overcomes the spring force and acts on the 2-4 band, locking the 2-4 band drum and small sun gear. When hydraulic pressure is applied between the servo piston and transmission case (2-4 band disengagement side), the servo piston is pressed toward the servo retainer side. The 2-4 band expands by its own spring force, releasing the 2-4 band drum and small sun gear.
When hydraulic pressure is applied simultaneously between the servo retainer and the servo piston and between the servo piston and transmission case, the servo piston is pressed to the servo retainer side as a result of the difference of the surface area between the two, releasing the 2-4 band drum and small sun gear. The 2-4 band operates during second gear and fourth gear.
Clutches - Low/Reverse
When hydraulic pressure acts on the low/reverse clutch piston, the low/reverse clutches are pressed tightly together, and the transmission case and the low/reverse clutch inner race are connected. The rotation of the front planet stops when the low/reverse clutch is applied. This brake operates during manual low (first gear) and reverse.
Intermediate Band and Low/Reverse Clutch Operation
One-Way Clutches
The forward one-way clutch on the front planet is a roller-type clutch. The one-way clutch allows rotation in one direction only. If the clutch tries to rotate in the opposite direction, the rollers are forced into the smaller slots of the gauge and the outer race is secured to the inner race. The low one-way clutch on the primary sun gear is a sprag-type clutch. If the clutch tries to rotate in the opposite direction, the sprags become wedged between the inner and outer races and rotation is stopped.
