A tire hoist is a device used to secure a spare tire to the undercarriage of a vehicle, usually a pickup truck or larger truck. Sometimes known as the spare tire hoist, this system allows a user to place a tire and wheel on the ground beneath the vehicle, place a block through the center of the wheel, and hoist up the tire by retracting a chain or cable. The retraction is done by turning a screw device, which is usually operated with a long pole or tire iron.
A mounting plate is affixed to the chain retraction system, which is mounted on a solid part of the undercarriage of the vehicle. The chain of the tire hoist system will dangle downward once the retraction system is mounted, and the block or brace can be positioned in the center of the wheel. As the chain retracts, the tire will be lifted until it hits the undercarriage of the car; the chain can be retracted until the tire stops, and then it can be tightened. Once the tire is in place, the tire hoist chain will hold it in place, even over rough roads and through vibrations.
In order to operate the tire hoist, a key in the form of a long pole or tire iron is used. In many cases, this pole must be slid through an access hole on the rear bumper of the vehicle and slotted in place on the chain retraction system. Once in place, the pole can be turned, thereby activating the screw system that will move the chain or cable in either direction. Very often the hole in the bumper will be stoppered to prevent theft of the tire; a key must be used to unlock and remove this stopper so the pole can be inserted. The tire should be lowered to the ground and removed from the undercarriage before a user begins changing out a flat tire.
The size of the tire hoist will vary according to the type of vehicle for which it is designed. Smaller hoist systems will be appropriate for small and mid-size pickup trucks, while much larger trucks as well as RVs will require a tire hoist system designed to secure a heavier tire and wheel. Most systems will be sold with information that indicates the weight capacity of the unit. Exceeding this capacity puts the user at risk of damaging the hoist system as well as the tire and wheel being suspended from it.
