Know About Tire-Changing Machines

Technically speaking, the term “tire” refers to only the doughnut-shaped, piece of black rubber which contacts the road as you drive. The tire is only one portion of the entire wheel assembly. The wheel, also called the rim, is usually made of steel or aluminum and sits in the middle of the rubber doughnut. The edges of the wheel have raised lips, on which the tire sits, and the portion of the tire that rests against the wheel is called the bead. The first step in changing tires is to “break” the bead. After removing the valve stem to deflate the tire, you place the shoe of the bead breaking system against the lip of the tire, just above the bead. The shoe forces the tire off of the lip of the rim. Next, the wheel is secured face-up on the front of the machine by the table clamping system, which grips the wheel under the lip. Some newer machines will include a tire changer wheel lift system, which raises the wheel assembly automatically, making heavy truck tire assemblies easier to handle.

After securing the wheel, the bead of the tire is lubricated to prevent damage. Then, using a pry bar, pull the bead up and over the wheel remover arm. Repeat for the other bead.

After the new tire is slipped over the rim, a new valve stem is inserted so that the tire can be inflated. The old valve stem can be reused, but a good mechanic will replace it each time the tire is taken off the wheel. It is often necessary to hold the tire up, so it can be inflated. After mounting, the new tire will need to be balanced using a machine balancer before it is reinstalled on the vehicle. It may also be necessary, if the customer approves it, to check the alignment of the vehicle using a wheel alignment lift.

The process described above involves using an automated tire changing machine, but tire can also be changed manually. Portable tire change kits and assemblies are widely available, and generally retail for under a hundred bucks. It is important to keep in mind, however, that using a portable tire change kit requires great care in order to avoid damaging the bead. An automated machine has safety features built-in to help avoid damaging the tire, but a manual kit does not.