http://www.europeantransmissions.com/the new genaration of a...
The automatic gear change is electronically controlled, resulting in virtually no discernible interruption of tractive power.

gear-change - automatic
http://www.buzzle.com/articles/automatic-transmission-proble...
Since you do not have any role in gear-change when using a vehicle with automatic transmission, the chances of the gears getting faulty due to human error are non-existent.

ili: automatic transmission
http://en.wikipedia.org/wiki/Automatic_transmission
An automatic gearbox is one type of motor vehicle transmission that can automatically change gear ratios as the vehicle moves, freeing the driver from having to shift gears manually.

http://www.westwardscania.com/trucks/main-components/transmi...
All automatic transmissions have options for PTO mounting.

Ili: gear-change - automatic
http://www.buzzle.com/articles/automatic-transmission-proble...
Since you do not have any role in gear-change when using a vehicle with automatic transmission, the chances of the gears getting faulty due to human error are non-existent.