I just got my new Trampa 1:7 Helical gear drive and was very disappointed when I went on my first ride and the thing was ear piercingly loud. I have spent the past few nights playing with the backlash and re-greasing the gears with no luck. It turned out that the backlash was not the problem at all. The problem comes from the way trampa mounts their gear drive system to their trucks. They use these “things” that allow the user to adjust the backlash and then tighten four bolts on the back of the drive. This squshes the rear “thing” into the front one.
The problem I was having is since the large gear is bolted to the wheel, which is bolted to the axle, The large wheel is perfectly perpendicular to the axile like it should be. Since the gear drive housing / small motor gear is attached to the axile using these “things”, there is opportunity for the drive housing / small motor gear to get tightened down at an angle offsetting it from the larger gear. I was very careful when installing these drives originally to tighten the four bolts in a uniform and crisscross manner but I guess that was not good enough. I was able to see that the gear drive was not parallel to the wheel. This causes the small gear to not mate perfectly to the larger gear. Since they are not aligned, the two gears mate at an angle causing the drive to be EXTREMELY loud.
The way I was able to fix this was by removing the wheel / drive cover / cleaning out the old grease, Loosening the four gear meshing bolts on the back of the drive, Reinstall the wheel without the drive cover, make sure the wheel is bolted down tight as well as the axle nut, Playing around with the tightness of the four bolts until I was able to get the drive parallel with the wheel. When I thought I had it, I would punch the throttle while the wheels were up in the air to listen for improvements. Eventually, I was able to get the drive quiet as a helical drive should be.
I have two questions, why would Trampa ship me a new gear drive with a new motor already installed and not set the backlash for me already? And why is this not a more common issue? I have only seen one other person on the forum with the same problem with no solution.