See also:

Hitches
Do not use a hitch that clamps onto the vehicle’s bumper or attaches to the axle. You must distribute the load in your trailer so that 10–15% of the total weight of the trailer is on the tongue. ...

Damage
Periodically inspect the tire treads and sidewalls for damage (such as bulges in the tread or sidewalls, cracks in the tread groove and separation in the tread or sidewall). If damage is observed ...

Compass calibration adjustment
Perform compass calibration in an open area free from steel structures and high voltage lines. For optimum calibration, turn off all electrical accessories (heater/air conditioning, wipers, etc.) ...