[Christ]

Using the OD lockout on trucks while towing actually has nothing to do w/ the TCC... it's due to the fact that the transmission will constantly be shifting between OD and the next lowest gear, and that makes for added wear and heat, which will damage the transmission.

On most transmissions, TC lockup doesn't occur unless the selector is in the highest range, so if OD is deactivated, so is CLK.

I will re-re-reiterate once again that the ability to control the TCC will result in less wear because it won't engage/disengage every time you load the engine or when you let off the accelerator to slow down 1 or 2 seconds to give the guy ahead of you some cushion space.