Towing Issues: car dolly, car dolly, tow dolly

Question
Hello, I have seen one time a 1999 toy truck on a tow dolly  
back up on to the dolly , IS THIS SAFE ?  I know the wheel
MUST BE LOCK . Thank you for the answer . Dave

Answer
If it was 2wd and the rear drive wheels were in the dolly that is okay but I would not advise a 4wd without disconnecting the drive shafts (front or rear depending which is in the dolly). There are debates over 4wd with manual transfer cases in neutral or other methods but the only true method, in my opinion, that will eliminate any potential damage is disconnecting the driveshaft.