11-09-2020, 09:52 AM
Even though I stripped and restored the 4 speed crash box on my RP a few years ago ( i replaced the input output and intershaft bearings) there was no apparent wear to any of the gears even after 80+ years, even to the 1st/2nd gears and those on the layshaft. What is interesting about this particular box is the fact that the 3rd/4th gears both on the mainshaft and layshaft are effectively locked together by the chevron gears and meshing is done by the gear dogs not the teeth. Both the layshaft chevron gear and mainshaft chevron gears move as a pair dependant on the selector movement. The input chevron gears do not move and the design removes all the thrust which sadly wasn't carried over to the later sunchromesh gearbox. Layshaft thrust and subsequent wear was a source of subsequent failure of the later boxes.