Transmission of Harleys with IOE two-cylinder (F and J models) and V models

These are classic 3-speed transmissions with sliding gears on the main shaft. The transmission main shaft´s left side runs in the third gear bushing and is bearing supported on the right in the transmission housing. On the countershaft the complete gear set runs roller bearing supported. The power from the clutch is transmitted from the main shaft to the positive-locking slider gear and, depending on the position, via the gear pair of the 1st or 2nd gear ("slider pinion") to the auxiliary shaft. The power is returned to the chain sprocket via the 3rd gear gear pair, which is located between the clutch and gearbox on the outside of the 3rd gear sprocket on the main shaft. For 3rd gear, the sliding sprocket is pushed directly into the 3rd gear sprocket, the power transmission goes directly from the clutch to the chain sprocket. The gear ratio in 3rd gear is therefore 1:1. The sliding gear must be carefully engaged with every shift and is prone to wear. The Cyclery has an optimized version for improved engagement. Wear-related metal flakes in the gear oil require frequent oil changes. As with all Big Twins, the rear chain runs on the left.