Yep, the pinion gear on the back one is pressed out a little, then pressed on
to the little part of the pinion that sticks out the back of the front one...both going into one DeWalt. They have a spare that uses a little shaft collar, which would be easier than pressing it on. There used to be two dewalts there, as you can see the mount for the other one, but one was taken out and this configuration was used...not positive why, maybe someone that was on the team this year can answer.
Here's the best pic I could get of it....
