Abstract: A control system/method for controlling the automatic or semi-automatic shifting of a range type compound transmission (10) is provided. The control utilizes a processing unit (106) requiring only two speed inputs, indicative of input shaft (16) and mainshaft (28) rotational speeds, to command both simple and compound shifts and to confirm the execution thereof.

Abstract: A control (220) for providing a dual pressure source (236) of pressurized fluid to a pressurized fluid operated shift actuator (30) for a mechanical change gear transmission (202) is provided.

Abstract: A blocker-clutch assembly (10) includes an openly porous, pyrolytic carbon composite friction material (74) configured for optimum performance and, therefore, prevention or substantial prevention of nonsynchronous engagement of positive clutch members (12,14) due to premature unblocking of blocker tooth ramps (48-54). The composite friction material is formed to be resilient in direction normal to its friction surface (76b), is cut into segments (76), is bonded to a frustonconical surface (62) in a manner preserving the resiliency and with the segments circumferentially spaced apart, and is configured to control engagement force thereon in a range of 150-300 pounds per square inch (10-20 Kg/cm.sup.2).

Abstract: A control system (158) for a multi-speed splitter type change gear auxiliary transmission section (14) of a compound transmission (10) of the type permitting preselection of a selected auxiliary section gear ratio is provided. The control system includes an operator actuated selector valve (160) for selection of a desired auxiliary section gear ratio and for selectively pressurizing or exhausting first (2) and second (3) selectively pressurized and exhausted fluid conduits which are directly fluidly connected to first and second (186 and 184) inlet ports at the remotely located actuator assembly (152). The actuator assembly (152) includes pistons (144 and 150) for assuming at least three selectable positions corresponding to engagement of one of at least three selectable auxiliary transmission section ratios and is enclosed in a valve body housing (170) having enlarged cavities adjacent the inlet ports (182, 184, 186) to define enlarged fluid reservoirs (R.sub.1, R.sub.2, R.sub.

Abstract: A vehicle component such as a transmission blocker ring (81) having an improved friction material (56) is provided. Friction material (56) comprises a composite of from about 25% to about 75% by weight of a flurocarbon polymer and from about 75% to about 25% by weight of substantially uniformly dispersed ceramic fiber and which is provided with controlled crystallinity by reason of having been cooled at a rate of less than about 20.degree. C. per minute after having been sintered at a predetermined sintering or annealing temperature and time for the friction material.