Check sequence
1. Before each trip, carefully inspect the wheels of the car and their fasteners. Each wheel is attached to the hub with four bolts. Press firmly on the side of the wheel with your foot, rocking the machine laterally. If the wheel bolts are not tightened, it will begin to swing on the hub. At the slightest suspicion of loosening of the wheel fastening, check the tightness of the bolts (tightening torque see "Wheel - replacement"). Wheel rims must be free of cracks and signs of deformation. Tires must not have cuts, delaminations, ruptures, bulges («hernia»), protrusions of the cord.
Note. In the absence of mechanical damage to the tire, its suitability for operation is determined by the height of the tread pattern.
2. Visually determine the possibility of further operation of the tire by the indicator protrusions in the grooves of the tread pattern.
The protrusions are 1.6 mm high. As soon as the tread height is equal to the height of the ledge, the tire must be replaced.
3. The indicators are located around the entire circumference of the tire at some distance from each other. We find them by symbols in the form of letters «TWI» or shooters «up» on the sidewall of the tire.
4. The residual height of the tread pattern is determined by eye or using a caliper depth gauge.
Thus, it is possible to compare the degree of tread wear at the edges of the tire and in its middle. Accelerated wear of the middle part of the tread indicates the operation of the tire with increased pressure, and rapid wear of the inner or outer part of the tread indicates the need to adjust the wheel alignment. With intensive wear of one of the wheels, it is possible that the suspension elements or the power elements of the car body are deformed.
Warning. According to «Appendix to the Basic Provisions on the admission of vehicles to operation and the duties of officials to ensure road safety», the operation of a passenger car is prohibited:
- if the tire tread height is less than 1.6 mm;
- with tires that have external damage (breaks, cuts, breaks) exposing the cord, as well as delamination of the tire carcass, delamination of the tread and sidewall;
- if there is no mounting bolt or there are cracks in the disk and wheel rims, there are visible violations of the shape and size of the mounting holes;
- if the tires do not match the model of the vehicle in terms of size or permissible load;
- if tires of different sizes, designs are installed on one axle of the car (radial, diagonal, chamber, tubeless), models with different tread patterns, studded and non-studded, frost-resistant and non-frost-resistant, new and retreaded tires.
5. The appearance of vibration felt on the body or steering wheel when the vehicle is moving at a constant speed over 80 km / h may be due to an imbalance of one of the wheels. To identify the cause, we check the wheel balance in a tire shop. If the vibration is caused by disk deformation, tire damage or uneven wear, replace the tire or disk.