So evidently I can't even get a Lego Rover to work correctly.
I've got to the point where the three parts are connected into a rolling chassis. And I stopped there to make sure everything is correct, but there is a problem.
Neutral, everything is as it should be.
In R, diff in L or H, it rolls fine... either direction.
In D, L or H, it chatters a bit, then builds up a lot of tension, enough that the wheels go spinning when you lift it up.
When it is in full neutral in the t-case and in the gearbox, it rolls fine, and all the gearing works, bypassing the t-case and transmission as it should.
The same problem is evident if you put drive to the transmission, or the engine, or the wheels.
It seems like gear 1 and 2, shows up in 4th.
Anyone fix something like this?