Wheel Hub: Locations

WM 4X00IN Central wheel lock: Component assessment

Central wheel lock: Component assessment

Information on component assessment

The following illustrations compare central wheel lock components as they normally look on vehicles that have been driven with components that show signs of excessive wear.

The following applies to the wheel hub : The wheel hub must always be replaced if the loosening torque of the relevant central bolt is less than 400 Nm (296 ftlb.) or if the driving pins can be turned by hand. It really doesn't matter how the wheel hub looks in this case.

Prerequisite: The central bolt was originally tightened to the prescribed tightening torque and the vehicle has since been driven.

The following also applies: If the vehicle that is being checked shows at least one sign of wear as shown, the affected component and other components, if necessary, must be replaced in accordance with the relevant instructions.

Wheel hub assessment

The wheel hub is assessed in three steps:
- Check the actual wheel hub (direct check)
- Check the wheel hub based on the appearance of the cone ring on the central bolt (indirect check)
- Check the wheel hub based on the appearance of the wheel cone (indirect check)

1. Check the wheel hub.
Examine the cylindrical surface of the wheel hub in the area in which the cone ring on the central bolt sits when the wheel is fitted => Checking wheel hub.





Checking wheel hub





Information

If it is not possible to determine clearly based on the contact pattern of the wheel hub whether the wheel hub looks normal for a vehicle that has been driven or whether it shows signs of wear, the cone ring on the central bolt and the conical area on the wheel must be examined in order to further assess the wheel hub (indirect check on wheel hub, see Steps 2 and 3).

2. Check the wheel hub based on the appearance of the cone ring on the central bolt ( => Checking cone ring on central bolt ).





Checking cone ring on central bolt





3. Check the wheel hub based on the appearance of the wheel cone ( => Checking wheel cone ).





Checking wheel cone





Assessment of wheel adapters, wheel and brake disc

1. Check wheel adapters => Checking wheel adapters.





Checking wheel adapters





2. Check the contact surface for the brake disc on the wheel ( => Checking wheel contact surface ).





Checking wheel contact surface





3. Check the contact surface for the wheel on the brake disc ( => Checking brake disc ).





Checking brake disc