Fifth Gear
In Fifth gear, the UD (1) and OD clutches (2) are applied to provide input torque. The UD hub is splined to the rear sun gear. When the UD clutch is applied, the UD hub and rear sun gear are driven. The OD hub assembly is splined to the front carrier/rear annulus assembly. When the OD clutch is applied, the OD hub and front carrier/ rear annulus assembly are also driven. With the rear sun gear and the rear annulus driven at the same speed and in the same direction, the entire planetary gear set is locked and rotating as one unit. The rear carrier/front annulus assembly rotates as an output member in direct drive, or 1:1.
Power from the main centerline transfers to the underdrive compounder gear set annulus by way of the transfer gears and the underdrive shaft. The direct clutch (3) is applied to drive the underdrive compounder sun gear at the same speed as the underdrive annulus. With two members driven, the underdrive compounder gear set operates in direct, or 1:1.
The main centerline ratio of 1:1 is multiplied by the underdrive compounder centerline ratio of 1:1. As a result, the ratio through the entire gear train to the final drive in Fifth gear is 1.00:1.