This procedure will guide you through the steps to fixing a loose caster (wheel) on the Goodnature X-1.
To tighten a loose caster, first remove the black cap just above the wheel, you can pry it off using a flat- head screwdriver. Using two, 3/4” open end wrenches, place one wrench on the top nut and the other wrench on the nut on the bottom of the casters post. Tighten the wheel’s top nut as you hold firmly onto the bottom nut with the other wrench. Tighten the nut as tight as you can.
To replace a defective caster, remove the nut and washers on the top post and replace the caster. When you reattach the washers and nut, make sure the washers are put on in the same order as they were taken off; tighten the nut on top tightly. Reattach the black cap using a plastic, rubber, or wooden mallet to seat it.