An all-terrain vehicle (ATV) uses many bearings in both its engine and chassis design. Other ATV bearings are used in the many attachments and optional components that are available for the ATV. Wheel bearings, axle bearings and bearings used in the neck to support the steering components are but a few of the ATV bearings used in the manufacture of an ATV. The engine in an ATV uses rod and main ATV bearings, as well as bearings to support the transmission gear clusters and the power output shaft.
Nearly every component on an ATV that spins, turns or rotates is fitted with some type of ATV bearings. The ATV bearings provide support with the loss of friction that allows the ATV to operate with great durability from the individual components. While some of the bearings require frequent lubrication through greasing, many ATV bearings are what is known as sealed bearings. These are bearings that are pre-lubricated by the manufacturer and are assembled in a way that the grease is permanently sealed inside of the bearing. This type of bearing is maintenance-free and requires no further greasing by the operator.
Some ATV bearings, such as wheel bearings, require occasional repacking. This entails removing the wheel hub assembly and removing the bearings from the inner and outer locations within the hub. The old grease should be cleaned from the bearings, as well as the inside of the hub before the repacking of grease is begun. It is never recommended that solvent be used to remove the grease from the bearing as some solvent may remain behind and cause premature failure of the bearing. Once the bearing is totally clean of the old grease, the bearing is packed full of new grease and then replaced into the hub assembly.
There are two types of bearings: roller and ball bearings. Roller bearings are comprised of long, barrel-like bearings that are wide at one end and tapered to a smaller end. The bearings are used primarily when more support is required from the bearing over a wider area, such as with a wheel bearing. A ball bearing uses round bearings that provide a minimum of support, however, the bearing does allow a component to move with ease, such as in the steering components of an ATV. While most factory-produced ATVs use steel bearings, many of the professional racing machines use ceramic bearings to save on weight.