When wired correctly the solenoid cannot engage OD until the vehicle reaches a predetermined speed. This prevents the solenoid from engaging in reverse.
Key words here
"When wired correctly...". I plan on wiring my next one so that others can drive my truck. As it is set up now, I can split shift to 6 forward gears. The danger here is that you are in OD, say at a stop on an (even) slight hill. Rolling backwards would chew up the expensive and increasingly rare gears. I bought a spare B-W overdrive and the od was completely chewed up I suspect by not having the od properly wired. Some may call my way of doing it risky, but ten years after a home rebuild and vigilant daily driving only vehicle of 60 K miles the od is going great.
That said I totally concur with Cletis, set the od up properly according to the manuals.
Cosmo
