Head over to the southern Queen's Hives and recover the wagon wheel. It's half-buried in the ground at -2712, -547, -1159 . When you click on the wheel you'll also receive the recipe scroll Wagon Wheel Repairs (level 10 Artisan required).
Repair the wheel. This requires a Woodworking Table, or Sawhorse, which can be found at the New Combine Foothold at -3781, -783, -79 . Any level of Durability will repair the wheel.
Return to Scout Master Kilkarn to complete the quest.