Since I was driving this (without a KD) for a while...
It depends on your speed (via governor) and load on the drive train (some of it you can control with your gas pedal/clutch, in certain situations)
While normal driving - it shifts up and down just fine - no need for a KD.
Only when you want to force it, to shift down (at a certain speed and load) - let's say you want to go up a hill or overtake a car in lower gear - that's when the KD would come into play.
But actually I never really missed that feature. The 261 has a ton of torque, and the only time I was driving mountain roads, I locked out the OD via the cable anyway.
Frank
Edit: just found the diagram I used back than on
OD diagram
