When replacing a disk, one should take into account not only its width and diameter, but also the pressing depth. The pressing depth is the distance from the middle of the disc to the contact surface of the wheel disc to the brake disc.
All disc wheels are made with an annular ledge. The annular protrusion is a bead pressed onto the landing shelf, which, even with a very sharp turn of the car, does not allow the disc to squeeze the tubeless tire.
When installing tires or rims that are not listed in the technical passport, bi iecrn should be the corresponding entry in the documents for the car. As a rule, this requires the permission of the manufacturer.
Attention! Technological progress does not stand still. It cannot be ruled out that the tires of older vehicles may have different pressures than those specified in this manual, or other equipment with tires and rims is allowed. It is recommended to clarify the relevant information in specialized workshops.
Attention! According to existing legislation, it is allowed to use tires with a residual pattern height of at least 1.6 mm along the entire tread tread. For safety reasons, it is recommended to replace summer tires already at a residual tread height of 2 mm, and winter tires at 4 mm.
Tire pressure - check
1. Check pressure only when tires are cold. If the pressure in the tire has decreased, then check the tire valve and the tire itself by pre-inflation.
2. Check the tire pressure at least once a month and also as part of the service, referring to the tire pressure data plate, which is attached to the door pillar on the driver's side.
An additional tire pressure check should be carried out before every long trip because thermal expansion increases the load on the tires.
The pressure in the spare wheel must match the pressure in the tires of the installed wheels.
All overpressure data refer to cold tires. Excessive pressure that appears in the tires during a long trip, which is approximately 0.2-0.4 bar, does not need to be relieved.
For vehicles with automatic transmission or air conditioning in the front wheels, a pressure of 0.1 bar above normal is recommended.
With a sporty driving style, it is recommended to increase the pressure in the rear and front wheels by about 0.2 bar.
Winter tires are usually operated with overpressure, i.e. approx. 0.2 bar above normal. The values recommended by the winter tire manufacturer must also be observed.
If winter tires have a speed limit, the corresponding maximum speed must be indicated on a sticker that must be within the driver's field of vision.
Wheels and tires - symbols
16.0 Example of rim designation | 16.0a Example of tire designation |
An example of the designation of rims: 5½J x 14 4 CH 36
5½J (A) - wheel size in inches.
J (IN) - designation of the height and contour of the annular protrusion (sides).
x - the designation of a solid disk.
14 (WITH) - the diameter of the disc in inches.
4 (D) - number of holes for wheel bolts.
CH (E) - protective profile for tubeless tires.
36 (F) - pressing depth 36 mm.
The pressing depth is the distance from the middle of the disc to the surface of its contact with the brake disc or drum.
The permissible lateral run-out of the bead flange G of the rim is 1.2 mm.
Permissible beating of the landing shelf in height - 0.8 mm.
195 - tire profile width in mm.
/70 - height to width ratio (the height of the tire profile is 70% of the width).
If there is no special profile height designation, (e.g. 155 R 13), then this means that in this case the usual or «normal» ratio. For radial tires it is 82%.
R - radial tire.
14 - landing diameter in inches.
89 is a number indicating the allowable load on the tire.
Attention! If there is M+S between designations 14 and 89, mo is a tire with a winter tread pattern.
H - the letter indicating the maximum permitted speed for these tires (in this case up to 210 km/h).
The letter indicating the maximum permitted speed for these tires is placed after the tire size. The designation of the maximum permitted speed applies to both summer and winter tyres.
Letter designations of the maximum permitted speed for tires:
Letter designation | Permissible speed |
O | 160 km/h |
S | 180 km/h |
T | 190 km/h |
H | 210 km/h |
V | 240 km/h |
W | 270 km/h |
Date of tire manufacture
The date of manufacture is stamped on the tire as a manufacturer's code.
Example: DOT CUL2 UM8 4400 TUBELESS
DOT - Department of Transport (US Department of Transportation).
CU is the abbreviation for the tire manufacturer.
L2 - tire size.
UM8 - tire construction.
4400 - release date, 44th working week 2000
Note: If instead of a 4-digit number code only a 3-digit number followed by a symbol is shown (, this means that the tire was produced in the past decade. For example, designation 509 (stands for Production Week 50, 1999.
TUBELESS - tubeless tire (TUBETYPE - tube tire).
Attention! From 10/98, new tires must additionally have an ECE control number (Economic Commission for Europe) UN, which is applied to the sidewall of the tire. This number confirms that the tire complies with the ECE standard. If after 10/98 tires without an EEC control number are installed, then the vehicle operating permit will be cancelled.
Wheel replacement and balancing
16.0b Changing wheels
It is impractical to change the direction of tire rotation when changing wheels, because Tires are only run in to the new direction of rotation after heavy wear. On some tire models, the direction of rotation is indicated by an arrow on the sidewall of the tire. In these cases, the specified direction should be strictly observed.
With noticeably greater wear on the front wheels, it is recommended to swap them with the rear ones. This ensures approximately equal service life of all 4 wheels.
Attention! Use a torque wrench to tighten the wheel bolts. Its use ensures uniform, with the same force, tightening.
Do not replace tires individually, but at least both tires of one axle. In this case, tires with a higher tread depth must always be installed at the front.
Attention! When replacing or removing tubeless tires, for safety reasons, the valve must also be replaced.
Light alloy wheels are protected against corrosion by a layer of clear lacquer. When changing wheels, take care not to damage this protective film. If necessary, paint over the damaged area with clear varnish.
3. Mark the position of the wheel on the hub with a marker before removing it. When installed, a balanced wheel can be put in its original position (see illustration).
16.3 Mark the position of the wheel on the hub with a marker before removing it. When installed, a balanced wheel can be put in its original position
4. Lubricate front and rear of wheel centering seat on hub with a thin layer of bearing grease each time a wheel is removed. Thus, it is prevented «accretion» wheels to hub.
5. Clean dirty wheel bolts and lubricate the surface of their heads to the disk. Do not lubricate the threads of the wheel bolts.
6. Install the wheel on the hub, following the marks made before removal, and tighten the wheel bolts in a cross pattern in several passes.
Attention! Tightening the wheel bolts on one side with different torques can cause the wheel to warp on the hub. The tightening torque for the wheel bolts is 90 Nm.
Balancing
Balancing is necessary to even out different weight distributions and material inaccuracies. In the process of movement, unbalanced wheels manifest themselves through shocks and shaking. Steering wheel shakes at high speed.
As a rule, this jitter occurs only in a certain speed range and stops when the speed increases or decreases.
Over time, wheel imbalances can lead to suspension, steering, and shock absorber failures.
It is necessary to perform wheel balancing every 2 years and after every tire repair, because due to tire wear and repair, the weight distribution of the tire material changes.
Some tips for caring for tires
Tires have a peculiar «memory», and mishandling them, and this includes, for example, quick or frequent crossings over curbstones or rails, often results in their failure. And this happens only some time later and at the most inopportune moment.
Tire cleaning
Do not wash tires with a steam jet. If the nozzle of this device is held too close to the tire, then its rubber layer is irreversibly destroyed within a few seconds, which cannot be repaired even by applying cold water. Tires cleaned in this way must be replaced for safety reasons.
Tires that have been in contact with oil or grease for a long time must also be replaced. In this case, the tire first swells, and then returns to its normal shape and looks intact on the outside, but the tire's load-bearing capacity is reduced.
Tire storage
Tires should be stored in a cool, dark and dry place. They must not come into contact with lubricants, oils or fuels.
Store wheels lying flat or suspended from rims in a garage or basement. If tires are not mounted on rims, they must be stored in a standing position.
Increase tire pressure slightly before removing wheels (by about 0.3-0.5 bar). For winter tires, use your own rims, since remounting tires for summer rims does not justify itself in terms of economy.
Tire break-in
The new tires have a particularly smooth surface. This is due to the manufacturing process. For this reason, new tires, including a new spare wheel, must be run in. During the running-in process, as a result of the onset of abrasion, the smooth surface becomes rough.
Before driving the first 300 km with new tires, the driver must be especially careful when driving on wet roads.
Anti-skid chains
The use of snow chains is only permitted on the driving (front) wheels.
Attention! Snow chains must not be fitted to wide tires or to standard tires on vehicles with a 16-valve engine.
Only snow chains approved by the vehicle manufacturer must be used.
Driving speed with snow chains must not exceed 50 km/h. On roads without snow drifts and ice, the chains must be removed.
Incorrect tire wear
For front wheels, slightly more wear on the shoulder of the tread than wear on the middle of the tread is normal. Moreover, due to the slope of the road, the wear of the tread shoulder facing the middle of the road (for the left wheel - the outer shoulder, for the right - the inner), may be more pronounced (see illustration).
16.0v Tread shoulder wear | 16.0g Sawtooth tire wear |
Uneven tire wear is mostly the result of too low or too high tire pressure. Uneven wear can be caused by improper wheel alignment, poor wheel balance, and defective shock absorbers and discs.
Sawtooth tread wear is usually due to vehicle overload.
First of all, you need to maintain the prescribed pressure in the tires. Moreover, the pressure check should be carried out at least once every four weeks.
Check pressure only when tires are cold. When driving fast, it rises due to the hai-roar of the tires. However, of course, you should not bleed air from heated tires.
If the pressure is too high, the middle of the tread wears out more, as the tread bends under the influence of high internal pressure.
If the pressure is too low, there is a greater load on the tread shoulder, and the middle of the tread flexes inward, hence more wear on the tread shoulders.
Incorrect wheel alignment and wheel imbalance give typical tire wear patterns, which are listed in the list of faults.
Vibration of the front of the car - elimination
Steering wheel shaking when driving at a certain speed is usually due to wheel imbalance.
Examination
7. Check tire pressure. Correct it if necessary.
8. Carry out a test drive. Try, as far as possible, to determine the defect that has arisen as accurately as possible, finding out when and under what conditions it manifests itself: at what speed, on the road with which surface, when driving in a straight line or when cornering.
9. Install the car on the goats.
10. Check wheel centering. With a properly seated rim, the wheel hub or brake drum must extend beyond the side of the rim and be at least flush with it. If not, then replace the disc.
11. Check the wheel suspension. Inspect the silent blocks, ball joints, shock absorbers and wheel rims to check their condition.
12. Remove the wheels and clean them. In this case, for example, stones stuck in the tread will be removed.
13. Inspect tires for «brake bald patches» on the protector. They are a worn tread pattern resulting from hard braking and driving with locked wheels.
14. Check the remaining tread depth of the tires and compare these data. If the tires of the front or rear wheels are abnormally worn, it is necessary to check the alignment of the wheels and adjust the camber and toe.
Attention! The wheel alignment must be checked by a specialist workshop, as only a suitable stand is available there.
15. Carry out a test drive to make sure the defect is corrected.
Axial runout of the wheel - check
16. With the vehicle raised, install a dial indicator on the tread tread and then on the sidewall. Slowly rotate the wheel by hand and watch the indicator. If the arrow deviates, make a mark with chalk on the corresponding place on the tire.
Rated values of admissible wheel runout:
- Maximum runout in height 0.8 mm
- Maximum lateral runout 1.2 mm
If the values obtained during the measurement are higher than the nominal values, then balance the wheel on a stationary machine. In this case, the wheels on the machine must be centered in the same way as on the hub.
Elevation runout elimination
17. Deflate the wheel and flare the tire.
18. Spin the tire on the rim 120".
19. Inflate the wheel and recheck the runout of the disc in height.
If the height runout is still above the maximum allowable value, move the tire again on the rim by 120°and measure the runout again.
If the runout is within the nominal value, then balance the wheel.
Axial runout of the wheel disc - check
20. Install the rim without tire on the machine or on the vehicle and center it. Fasten the dial indicator.
21. Check for runout in height and lateral runout of the disc. Pitch measurement (deviations in circular motion) is carried out on the landing shelf of the disk, and lateral runout - on the inside of the side flange. Indicator readings caused by material irregularities are not taken into account.
Runout ratings for steel rims:
- Maximum allowable runout in height 0.8 mm
- Maximum allowable lateral runout 1.2 mm
Runout ratings for light metal discs:
- Maximum allowable runout in height 0.25 mm
- Maximum allowable lateral runout 0.3 mm
If the readings obtained during the measurement exceed the nominal values, then replace the disk.
Installing wheels on a car
22. Install the wheels on a raised vehicle so that the point of maximum runout in height is at the top. Tighten the wheel bolts in this position in a cross pattern with a torque wrench to 90 Nm.
Attention! If the difference in wheel tire wear is negligible, then install the wheels with the least runout in height and the least unbalance on the front axle.
23. Take a test drive. If the vibration of the steering wheel is still present, then this may be a residual phenomenon that can be eliminated by balancing (running in) wheels without removing them from the vehicle.
Wheel balancing on a car
When balancing the drive wheels, be sure to put both wheels on the stand rollers.
Both wheels are driven by the vehicle's engine to ensure synchronism.
24. Take a test drive.
If vibration occurs in this case, then either one tire or several have a radial misalignment. With the help of the equipment that the workshops have, this distortion cannot be measured. In this case, the way out is to replace the front or rear tires. Be sure to replace both axle tires.
Tire valve check
25. Unscrew the protective cap of the tire valve.
26. Lubricate the opening of the valve with soapy water or spit it. If a bubble forms, tighten the spool 3 with the other end of the protective cap 2 (see illustration).
16.26 Tighten the spool 3 with the other end of the protective cap 2
1 - rubber cap
4 - valve
Attention! To tighten the valves, use only metal protective caps 2 valves. Metal protective caps can be purchased at gas stations.
27 Check the valve again. If bubbles continue to form and the valve no longer tightens, replace it (workshop work).
28 Screw on the new protective cap.
Tread check
Tires of balanced wheels, while maintaining the prescribed pressure in them, correctly adjusting the wheel alignment angles and impeccable operation of the shock absorbers, wear out approximately evenly over the entire tread. For uneven wear, see the Tire Fault List. It is not possible to say anything definite about the service life of tires from different manufacturers. this period depends on various factors, namely:
- road surface, tire pressure, driving habits,
- weather conditions.
Rapid tread wear is favored primarily by sporty driving, rapid acceleration and heavy braking.
Attention! Legislation requires treads to have a pattern height of at least 1.6 mm, namely, the depth of the grooves must be at least 1.6 mm throughout the tread. However, for safety reasons, it is recommended to replace tires already with a residual tread height of 2 mm.
If the tread height approaches the legal minimum residual height of 1.6 mm, the tire must be replaced. At the bottom of the longitudinal grooves of the tread there are marks of tire wear (TWI). The locations of the marks are marked on the sidewall of the tire with the letters TWI and triangles.
16.0d Tire tread wear
Attention! M + S tires are only effective in mud and snow when the minimum remaining tread height is 4 mm.
Attention! Check the tires for cuts and, if present, use a small screwdriver to set their depth. If cuts reach the carcass, then the steel cord of the tire begins to rust under the influence of penetrating water. Because of this, the tread can peel off from the carcass and the tire breaks. Therefore, for deep cuts in the tread, for safety reasons, the tires must be replaced.