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.