Try placing your gear vertically so the wheels are not running on an angle. If that doesn't work, place them further outboard. If that doesn't work, place your gear in a configuration that ensures an "upward" position (nose pointing slightly above horizon). If the problem persists yet, strut everything. If that doesn't work, try 4 wheels instead of 3, 6 wheels instead of 5, etc. If all of that fails, you may consider building a new plane.