I am working on a creation of combining the 42070 6x6 tow truck and the 42042 crawler crane by putting the crane on the back of the truck. It is mostly complete, and I'm just detailing it at this point. There is only one problem with it, though. I made the crane fully automized by removing all of the gears in the back half of the crane and put motors there instead. I also had to move the large turnable rotating piece on the bottom of the crane forward and matched the teeth on the edge with the tan 12t bevel gear. It turns, but the teeth slip and it turns a little too fast, which I couldn't solve. I removed all of the gears for turning and the turnable and tried putting in this:
and connected it to some gears to gear it down, but it didn't even turn under the weight of the crane. Any ideas to make it work? Also, an L motor is powering it