A gear speed change system includes an input shaft, an output shaft coaxial therewith, a first counter shaft disposed parallel to the input and output shafts, and a second counter shaft coaxial with the first counter shaft. The input shaft and the first counter shaft, and the second counter shaft and the output shaft are coupled at a fixed ratio, respectively. One of gear sets selectively couples the input shaft to the second counter shaft and the output shaft to the first counter shaft, respectively. A clutch is provided between the first and the second counter shafts. With this construction, speed changes by the first counter shaft, the second counter shaft, and the combination of the first and second counter shafts may be effected, thereby reducing the number of required gear sets as compared with that of the speed change steps. The first counter shaft and the second counter shaft may be replaced with each other.

A compound vehicular transmission having a main section and an auxiliary section which includes an auxiliary countershaft gear assembly having an auxiliary countershaft, a first auxiliary countershaft gear fixed to the auxiliary countershaft and constantly meshed with an output shaft range gear, and a second auxiliary countershaft gear selectively coupleable to the auxiliary countershaft and constantly meshed with an intermediate shaft output gear. A jaw clutch is provided for coupling either the auxiliary countershaft to the main countershaft, or the auxiliary countershaft to the second auxiliary countershaft gear. This allows fewer gears to be utilized to achieve a desired number of speed ratios. Since the auxiliary countershaft drive gears are clutched only when used, this arrangement reduces spin back speed of the intermediate shaft to accommodate smoother and faster shifting of the transmission. Alternative embodiments include the use of a two-speed master clutch splitter section or a two-position synchronizing clutch assembly as the input to the main transmission section.

The invention provides a speed changing apparatus for a working vehicle comprising branched transmission lines between an input shaft and an output shaft. Each of the transmission lines includes one or more synchromesh type change speed gear mechanisms and one hydraulically operated clutch.

A simple transmission (10) and compound transmission (100, 200, 300) having an extended range and/or number of gear ratios and minimized center distance and/or axial countershaft length is provided by the use of compounded countershafts ( 16, 116, 216, 316). Each of the compounded countershafts comprises a first portion (20) and a second portion (22) wherein the second portion telescopically surrounds the first portion and is supported for relative rotation thereon by bearing means (28, 128, 228, 328) carried by said first portion. In the compound transmission embodiments, the use of compounded countershafts allows the use of splitter-type auxiliary sections (114, 214, 314) and non-synchronized splitter jaw clutches (76).

A reverse idler shaft and washer assembly particularly suited for use in a compound transmission includes a lubricating washer having at least one notch for collecting and directing lubricating oil through a reverse idler gear bearing such that lubrication passageways are eliminated from the reverse idler shaft. The lubricating washer includes an annular region capable of supporting a clamping load through the inner race of the reverse idler gear bearing to resist rotation while allowing the outer race and the associated reverse idler gear to rotate freely.