Patent ID: 7384366

Claim:
A method of coordination of transfer case shifting operations with a transmission output: providing a transmission connected to a vehicle engine having a predetermined number of gear ratios which are selectable; providing a transfer case with an input from said transmission and an output to at least one drive wheel of a vehicle; providing said transfer case with a sun gear grounded to the inside of said transfer case, a ring gear connected to an input shaft, a set of planetary gears in mesh with said ring gear and in mesh with said sun gear, said planetary gears mounted on a carrier, an extension connected to said input shaft, and a shift synchronizer connected to said carrier on a first end and connected to said extension of said input shaft on a second end; said transfer case including at least two gear transfer ranges which are selectable; expanding the number of ratios available for shifting during operation of said vehicle by selecting a gear ratio from said transfer case which provides a final drive ratio above at least one of said number of gear ratios of said transmission during operation of said vehicle in the absence of driver input; and shifting said transfer case to one of said at least two gear transfer ranges.