Okay, current findings. After further tinkering trying to discern what those strange one way gears are, they appear to be a means to prevent the tank from rolling in the opposite direction from the current direction of travel. In other words, if you are climbing a steep hill and stop, the tank will not roll backwards under its own weight. This however, will mean that if you are descending an equally steep grade, you would freewheel downhill unless you applied reverse to check the rotation of the bell-shaped housing. Thanks to the link from MAUS45, I have an ESC on order. Just for laughs, I pulled the motor out and swung by a couple of the LHS's and asked about a replacement
, boy did that throw them for a loop! Needless to say, they all thought I was nuts, but admitted they never had anyone come in looking for parts for a 60lb tank. On a more serious note, I am going to see if one of my co-workers has a hand-held tachometer so that I can find out what the no-load RPM is on that motor (which is annoyingly unmarked), in case I ever should need or desire to replace the motor.
This is a video of the speed control at work, please excuse the crude camera work:
This is the motor at full tilt with 12V applied direct:
You can see the way the motor rocks in the housing and the linkage pops off because full power is applied so quickly.
Enjoy!
Mark