Abstract: A transmission range valve replaces a traditional spring bias with a pressurized fluid bias to prevent an unintended range change in the event of a significant fluid pressure decrease or loss. Because pressurized fluid is used both for biasing the range valve and for shifting the range valve to effect an auxiliary section range change, a pressure drop or loss of supply pressure will not result in a change of state of the range valve as may occur with prior art spring biased valves.

Abstract: A motor vehicle transmission control lever (2) is provided that carries switch means for controlling a system for braking the vehicle's engine or in combination: (i) switch means for controlling a cruise control system and (ii) switch means for controlling a system for braking the vehicle's engine. The switch means for controlling the cruise control system and the engine braking system are preferably mounted on a housing (10) secured to a handle or knob (6) that is secured to transmission control lever (2) for convenient operation by the operator.

Abstract: A fluid pressure actuated auxiliary transmission section (14) shift control system (230)/method is provided which includes control members to minimize the possibility of auxiliary section synchronized clutch (92, 128) damage by the main transmission section (12) being engaged during an auxiliary section shift. A range interlock assembly (258) is provided which will release the range slave valve (238) as the main transmission section is shifted into the neutral position thereof and preexhaust valves (300, 302) are provided which will exhaust the appropriate actuator chamber (222A, 224A) upon preselection of an auxiliary section shift.

Abstract: An improved mainshaft gear retainer assembly (66, 68) for a twin countershaft (18, 18A) transmission (10) having at least one pair of floating mainshaft gears (44-46, 48-50) positioned close together in groups of two and clutchable to a mainshaft (40) one at a time by positive clutches (54, 56, 58) is provided. The improved mainshaft gear retainer assembly prevents axial movement of the two closely positioned gears and reacts the axial forces on a clutched one of the mainshaft gears toward and away from the other mainshaft gear to the mainshaft by means of thrust surfaces (78, 124, 126, 128, 130, 132, 134, 136) which are all rotating, or tending to rotate, at the same speed as the clutched mainshaft gear and the mainshaft. The gear retainer comprises relatively simple components and allows easy assembly and disassembly of the mainshaft gears and gear retainers from the mainshaft.

Abstract: A control (100) for positioning and locking the auxiliary transmission section (13) of a compound change gear transmission (11) in neutral is provided. The control includes a selector switch (132) for activating or deactivating the control and a monitoring device (42) for sensing if the main transmission section (12) is in neutral. The control, once activated, will retain the auxiliary transmission section in neutral until the selector switch is switched to a deactivated position (M) simultaneously with the main transmission section shifted to neutral.

Abstract: An add-on forced lubrication system is provided for assembly to a standard transmission (10). The forced lubrication system comprises a drive adapter (48) mountable to end of a shaft (12) accessible from the exterior of the housing (14) through a removable cover (28), a pump (68) driven by said shaft by a pump drive shaft (66) received in said adapter and mountable to said housing at an interface (74) substantially identical the interface (29) of the removable cover, a first fitting (82) receivable in a first bore (40) communicating with the transmission sump (36) and normally closed by a first plug (42), a lubricant conduit connecting said first filling to the pump inlet (76), a second fitting (94) receivable in a second bore (44) normally sealed by a plug (46) and a conduit (96) connecting said fitting with the pump outlet (78).