Back-Up (Reverse) Gear

Back-up (reverse) gear




On engaging reverse, the selector fork moves the 5th/reverse synchromesh sleeve (20) along the synchromesh hub towards the freely-rotating reverse gearwheel (19). The synchromesh sleeve and hub then lock the reverse gearwheel (19) on the upper output shaft (C).
From the clutch, power from the engine passes via the input shaft (2), 1st gear (8) on the primary shaft (A) to the 1st gearwheel/reverse idler gear (14) on the lower layshaft (B). From here, it passes to the reverse gearwheel (19) on the upper layshaft (C) via the synchromesh unit and final drive pinion (6) to final drive (5).
This patented idea of combining the 1st gearwheel and intermediate reverse gear in a single wheel removes the need for a separate reverse idler shaft, so that synchromesh is also available in reverse.