Parts for Big Twin 6-speed transmission

From 2006 for the Dyna model series and 2007 for all big Twins from Harley-Davidson: the six-speed transmission! Traditionalists rub their eyes, but anyone who has tried it knows that even on high-torque motorcycles such as the two-cylinder V engines from Harley, more gears ensure smooth acceleration. A little movement in the foot also prevents venous disorders ...

As is now a good tradition with the large two-cylinder engines

..., the rear wheel drive remains on the left, output between the primary and gearbox housing. Inside the housing, however, the gear pairs of the individual gears are arranged according to size, as is customary in racing. On the main shaft, the smallest gear (1st gear) is on the far right, the largest (6th or direct gear) on the far left. Gears 2 to 4 are arranged in between, and vice versa on the auxiliary shaft. All gears are in constant mesh, and four pairs of gears are even helically toothed to reduce noise. In terms of production technology, a few operations are saved by making the gears of gears 1 to 4 form a single part with the main shaft.

Are there any weak points in the Harley-Davidson six-speed gearboxes?

None are known. As long as the oil is changed regularly, everything remains in the green zone. By the way, even if the gearboxes still have their own oil filling, they can be used like any other motorcycle gearbox with Full Synth engine oil with JASO MA2 specification.