[Zabco]

Don't you love it. Think you got one simple change to make and it cascades into an avalanche. Good thing this is a hobby, I'd hate to have to charge someone for the time involved in some of these changes.

As to your bearing problem. Would it be possible to cut a small groove in the axle shaft just outboard of the bearing and install a C or E clip to act as a stop. This is how the bearings in Tamiya trailer axles are held in place.