Wheel replacement
When changing wheels, it is impractical to change the direction of rotation of the tires. For some tires, the direction of rotation is indicated by an arrow on the side and must be observed.
It is recommended to replace the front wheels with the rear ones every 10,000 km. Thanks to this, all 4 wheels will have the same service life and the same wear.
Tighten the wheel bolts with a torque wrench only. This ensures that they have the same tightening.
Replace tires not individually, but at least on one axle. In this case, tires with a greater profile depth should be mounted at the rear.
Attention! For safety reasons, it is imperative to replace the rubber valve when changing or removing tubeless tires.
Remove any rust on the contact surface of the rim with a wire brush. To protect the wheel from corrosion, lightly lubricate the disc wheel seat on the hub front and rear with bearing grease every time you remove it.
1. Press the wheel cover out with a screwdriver or remove it by hand, depending on the design.
2. Before removing, mark the position of the wheel relative to the hub with chalk or a felt-tip pen in order to install the wheel in its same position during re-assembly.
3. The light metal rims are protected against corrosion by a clear lacquer finish. When replacing a wheel, take care not to damage it, if necessary, improve the coverage.
Attention! Bolts 1 (length L = 40 mm, K = 13.5 mm) designed for light metal disc wheels only, bolts 2 (length L = 21 mm, K = 10.5 mm) are used only for steel disk wheels. If light metal rims are additionally mounted and a steel disc wheel is supplied as a spare wheel, it is recommended that the corresponding spare wheel bolts be included in the tool kit.
4. Clean contaminated threads with a wire brush. Do not lubricate the bolts with oil and grease.
5. Before installing a light metal disc wheel, screw the mounting sleeve supplied with the spare wheel into the upper threaded hole.
6. Fasten the wheel bolts crosswise in several passes.
Attention! If the bolts are tightened one-sidedly or insufficiently, the wheel or hub may be overtightened.
7. Tightening torque: 110 Nm for steel and light metal rims.
8. Put on the wheel cover again. When installing, put on the cover in such a way that the valve fits more firmly into the cutout provided for it. Steel rims should only be used with mounted wheel covers to avoid damaging the tire valves.
9. With new wheels, retighten the wheel bolts after about 100 - 500 km with a torque of 110 Nm.
Anti-skid chains
The use of snow chains is only permitted on the rear axle. Remove wheel covers before fitting snow chains. Use only snow chains approved by Mercedes.
For vehicles with ASR traction control, a snow chain switch is used. When adjusting the height of the car, set the car to the highest ground clearance. Drive with snow chains at a maximum speed of 50 km/h. Remove snow chains on snowy and ice-free highways.
Tire care
It is known that tires have a so-called "memory", and their unskilled use, for example, fast or frequent driving over stone curbs or rail edges, often manifests itself much later as damage to them.
Tire cleaning
If possible, do not clean tires with a steam jet from a steam jet pump. If the nozzle of the steam jet pump is kept too close to the surface of the tire, a chaotic parabolic destruction of the rubber layer occurs within a few seconds. A tire 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. The tires swell first at the points of contact, and then return to their normal shape and look undamaged on the outside. However, their bearing capacity is reduced.
Tire storage
Tires should be stored in a cool, dark and dry place. They must not come into contact with oil and grease.
Store tires lying flat or rimmed in a garage or basement.
Before removing the wheels, slightly increase the air pressure in the tires (approx. 0.3–0.5 bar).
For winter tires, use their own rims, as changing tires to other rims is associated with additional costs.
Tire break-in
New tires have a particularly slippery surface. Therefore, new tires - this also applies to a new spare wheel - should be run in. During this break-in, the surface of the tires becomes rough as a result of initial wear. The first 300 km should be driven with new tires especially carefully, especially in wet weather.
Wheels - balancing
Every time a tire is remounted, the wheels must be balanced again to compensate for the different weight distribution and material unevenness.
During driving, the imbalance is manifested by vibration and rumbling. The steering wheel then begins to tremble.
As a rule, the vibration of the steering wheel appears only in a certain range of speeds and disappears when switching to lower or higher gears.
This kind of unbalance phenomenon over time can lead to damage to the axle joints, steering mechanism and shock absorbers. Be sure to balance the wheels every 20,000 km and after each tire repair, as the distribution of mass and material changes during tire wear and repair.
Incorrect tire wear
On the front wheels, slightly more shoulder wear compared to the middle of the tread is normal. Moreover, as a result of the slope of the road, the wear of the shoulders of the tires directed towards the middle of the road is much more pronounced (left wheel: outside, right wheel: inside).
Uneven wear is usually caused by too low or too high air pressure in the tires, but can also be caused by incorrect wheel alignment or imbalance, or a faulty shock absorber or rim.
Tire profile sawtooth wear is usually caused by overloading the vehicle.
First of all, pay attention to the correct air pressure in the tires, and at the same time check their condition at least every four weeks.
Check air pressure only on cold tires. Tire pressure rises as the tire heats up when driving fast. However, hot tires should not be deflated.
If the air pressure in the tires is too high, the middle of the tread wears out more, because as a result of the high internal pressure, the tire is more arched in the middle of the tread.
If the air pressure in the tires is too low, the tread wears more on the shoulders of the tire, and the middle of the tread becomes convex inward. As a result, there is more wear on the tire shoulders.
Incorrect wheel alignment and imbalance give a typical picture of tire wear.