Overdrive (O/D) One-Way Clutch (OWC) Mechanical Diode: Notes

WARNING: This page is about a different car, the 2011 Ford F550 Super Duty and 2011 Ford F450 Super Duty. However, it is still accessible from the selected car via links, so may be relevant.

The O/D OWC mechanical diode is a OWC which also acts as the coast clutch pressure plate. It provides direct drive through the O/D gearset when in power ON mode. It overruns in power OFF mode or when the O/D clutch is applied.

Engine torque is transmitted in 1st, 3rd and 5th gears while the selector lever is in the (D) position. The input shaft drives the O/D carrier clockwise. The O/D carrier has the coast clutch hub bolted to it which also turns clockwise. The O/D sun gear would turn counterclockwise, but is held from turning by the coast clutch mechanical diode. The input shaft turns the same speed as the center shaft and transmits torque through it.

In 2nd, 4th and 6th gears, the O/D clutch is applied, the mechanical diode overruns and holds the O/D sun gear fixed to the case. This causes the O/D planet to walk around the sun gear and over-drive the O/D ring gear.