I had the same problem on out Hurricane 31 S F53 chassis. We just got it back from the Ford dealer last week. At 7,000 miles the King pins needed replacement and the why was a top bushing was missing on the right wheel since the factory. Apparently reading the other motor home forums this is happens with some frequency. I paid for wheel balancing , they also replaced wheel bearings, front stabilizer bar was loose ( i might have the wrong term there), but I would get an occasional clunking in a turn, or over a bump, no adjustments needed for a front end alignment. Luckily it was under warranty except for the wheel balancing.
2015 Thor Hurricane 31S
2015 Jeep Wrangler Willy
Blue Ox Tow Bar and attachment Plate/SMI Brake System