Allison PTO operation
The 1000/2000 Series transmission utilize a 6-bolt PTO which operates like a PTO on a manual transmission. The only way to put the PTO in gear is to stop the truck. If the torque converter is in lockup (higher gears), the speed of the PTO drive gear is equal to engine speed (Lockup Mode). If in converter mode (lower gears, neutral, reverse), result is variable speed and torque/RPM is always lower than engine speed.