I installed bearings in the idler wheels and front axles. Both are much more solid. The first picture are the bearings and bolts used for the idlers. I drilled the inner idler half from the inside leaving just a very thin lip. I then pressed in two bearings in each wheel. I cut one of the original bushings in half to use as a spacer along with one washer. I re-drilled and tapped the steel plate to 5mm. These bolts have the correct length shoulder. For the front bearings, I used standard skateboard wheel bearings and short sections of plastic pipe with the correct size inside diameter. I had to lightly sand the front axle with fine wet/dry sand paper to make the bearings slide on easily. I sanded the hole in the transmission cover to fit the pipe inside. I glued the pipe to the tub and the transmission cover. The bearings are just press fit in the pipe. The motor/gearboxes are still easily removed.