US Patent 6955627 Multi-speed transmission and integrated drive transfer mechanism

A multiple speed transmission capable of producing five underdrive gear ratios, one direct drive ratio, four overdrive ratios, and four reverse ratios includes four interconnected planetary gearsets, multi-plate clutches and brakes controlling the gearset elements, and a coupler that changes between forward drive and reverse drive by holding and releasing alternate gearset components against rotation on the transmission case. The transmission in combination with a single-speed transfer case having either an on-demand transfer clutch, or a full-time all-wheel drive system, are formed in an integrated package.