Abstract: A change-gear transmission having an input shaft, a main shaft having at least one main shaft gear, a plurality of countershafts spanning between the input shaft and main shaft gear, and gear synchronizers between selectable gears. The bore of main shaft gears have a minimal radial clearance fit with its mating parts to prevent gear synchronizer wear, while the meshing between the input shaft gears and countershaft gears is equally distributed using a means to equalize the torque transfer between countershafts. The countershafts are rotatably supported and displace axially between bearing or bushing supports, while the meshed gears comprise a helical gear tooth arrangement to create axial load on the countershaft if excessive and uneven load is sensed in one countershaft over another. This presents a new and unique countershaft meshing design that allows multiple countershafts to achieve equal load sharing while permitting gear synchronizers use on the main shaft.

Abstract: A change-gear transmission having an input shaft, a main shaft having at least one main shaft gear, a plurality of countershafts spanning between the input shaft and main shaft gear, and gear synchronizers between selectable gears. The bore of main shaft gears have a minimal radial clearance fit with its mating parts to prevent gear synchronizer wear, while the meshing between the input shaft gears and countershaft gears is equally distributed using a means to equalize the torque transfer between countershafts. The countershafts are rotatably supported and displace axially between bearing or bushing supports, while the meshed gears comprise a helical gear tooth arrangement to create axial load on the countershaft if excessive and uneven load is sensed in one countershaft over another. This presents a new and unique countershaft meshing design that allows multiple countershafts to achieve equal load sharing while permitting gear synchronizers use on the main shaft.