Franchise agreements. Franchisors and franchisees are required to comply with the Franchising Code of Conduct. The Code applies to conduct occurring on or after 1 January 2015 in relation to all franchise agreements entered into, transferred, renewed or extended on or after 1 October 1998.
Generally speaking, overdrive is the highest gear in the transmission. Overdrive allows the engine to operate at a lower RPM for a given road speed. This allows the vehicle to achieve better fuel efficiency, and often quieter operation on the highway.
Automatic transmissions use mainline, governor, and throttle pressure valves to control and lubricate the transmission. Some of these have been replaced or work together with electronic controls. Governor pressure increases with vehicle speed. Older transmissions had mechanical governors that consisted of springs, centrifugal weights, and a spool valve to control this pressure. Governor pressure causes a transmission to upshift and throttle pressure causes it to downshift. Todayâs transmissions use solenoids for shift timing. Throttle pressure indicates engine load. Some transmissions use a vacuum modulator or throttle linkage to control the throttle valve. Late model vehicles use electric solenoids to achieve the same results. Shift Valves: Transmissions change gears by moving shift valves. Governor pressure works on one end of the valve and throttle pressure aided by a spring works on the other.