Running gear, axles, steering · Wheels, tyres, vehicle geometry · Wheels, tyres

Wheel change

⇒ 1.4.1 Wheel change, protecting wheel centring seat against corrosion

⇒ 1.4.2 Wheel change, installation requirements

⇒ 1.4.3 Wheel change, installation instructions for wheel change

⇒ 1.4.4 Wheel change, wheel installation

1.4.1 Wheel change, protecting wheel centring seat against corrosion

Applies to alloy and steel wheels

When changing a wheel, wheel centring seat should be waxed using wax spray to prevent corrosion between wheel centring seat and wheel rim ⇒ Electronic parts catalogue “ETKA”.

Remove wheel.
Thoroughly clean wheel centring seat on wheel hub and the centring ring of the wheel rim.

Apply wax to centring area -arrow- with a brush.

Ensure that only centring ring -arrow- but not contact surface of wheel rim has been waxed. Otherwise, the brakes will be soiled, which would reduce the braking efficiency.

Install wheel and tighten bolts or nuts ⇒ 1.5 Specified torques for wheel bolts.

1.4.2 Wheel change, installation requirements

Warming cold tyres to minimum fitting temperature

Warning

The minimum fitting temperature of a tyre should be between 15 °C and 30 °C in the core of the tyre.

To install tyres without damage, it is especially important to warm the upper part of the sidewall and the inside of the upper bead to at least 15℃.
This internal temperature is referred to as the core temperature.
Rubber is a poor conductor of heat. Therefore, a cold tyre must be left in an area with the correct temperature for a sufficiently long period so the inner rubber layers can warm up to at least 15°C.
The surface temperature of the tyre during the warming up phase is no indication of the internal temperature of the tyre.
To enable cold tyres to absorb heat from the ambient air as quickly as possible, they should not be stacked on top of one another. Instead, the tyres should be stored individually in order to allow the warm air to “circulate” around them effectively.
Tyres must never be placed in front of a radiator or hot air blower for warming, since this can very quickly lead to critical surface temperatures.
Heating the tyres without damage can only be achieved by heating with warm water or warm air (max. 50°C)!
If cold tyres (below 0℃) are transferred to a warm environment (above 0℃), a layer of condensation immediately forms on the surface of the tyre. This layer of condensation indicates that the tyre is intensively absorbing heat from its environment through the process of water vapour in the air condensing out on the tyre surface.
Once the layer of frost has thawed, condensate water forms. The condensation should be dried with a cloth so that the further warming process is not delayed due to a temperature drop caused by evaporation.

Warming times:

Tyres with a temperature of above 0°C must be kept at least at 19℃ for at least 2 hours.
Tyres with a temperature of below 0°C must be kept at least at 19℃ for at least 2.5 hours.

Warming recommendations:

If possible, tyres should be stored in the workshop 1 day before they are fitted (order preparation).
Store on an insulated base, pallet or on a similar surface raised from the floor.
Position the tyres individually to allow the warm air to “circulate” around them effectively.
Wipe off condensation
Never heat with a radiator or hot air blower!

1.4.3 Wheel change, installation instructions for wheel change

6C 2014–2017

Check to ensure that contact surfaces -arrows- on brake disc are free of corrosion and dirt.

Check to ensure that contact surface -arrow- on centring seat of brake disc are free of corrosion and dirt.

Check to ensure that contact surface -arrow- on inner side of wheel (rim) and also centring seat of rim are free of corrosion and dirt.
The lug seats^* in the holes for the wheel bolts and the threads of the wheel bolts must also be free of corrosion and dirt, oil or grease.

* The lug seat is the curved surface of a section of a sphere cut by a plane.

Check whether the wheel bolts can be easily screwed in by hand. The thread of the wheel bolts must not come into contact with the bore in the brake disc -arrow-.

If the thread of the wheel bolt touches the hole -arrow-, turn the brake disc relative to the wheel hub accordingly.

If necessary, remove dirt and corrosion:

Oil or grease from contact surfaces
Oil or grease from threads in wheel hub
Oil or grease from threads in wheel bolts

1.4.4 Wheel change, wheel installation

Protect wheel centring seat against corrosion ⇒ 1.4.1 Wheel change, protecting wheel centring seat against corrosion.

1 When fitting the wheel, pull in all wheel bolts uniformly by
hand.
2 Tighten diagonally to 30 Nm.
3 Lower vehicle onto floor. Use torque wrench to firmly tighten wheel bolts diagonally to specified torque ⇒ 1.5 Specified torques for wheel bolts.