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).

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).

1. Check actual 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. 

   Courtesy of PORSCHE CARS NORTH AMERICA, INC.

   Checking wheel hub

   Wheel hub assessment
   Looks normal and seems normal while driving	Excessive signs of wear
   Wide contact pattern  > Wheel hub OK  Cylindrical surfaces of the wheel hub -Arrows-  : > Minimum contact pattern width 10 mm On vehicles with low mileage, the contact pattern may not be continuous, but the width of the contact pattern must not be affected. > Wheel hub OK (1).  The discoloration can vary from shiny metallic to dark grey.	Linear pattern  > Wheel hub not OK  Narrow (linear) contact pattern that is uneven or only in spots on the cylindrical surface of the wheel hub -Arrow-  .
   Courtesy of PORSCHE CARS NORTH AMERICA, INC. Wheel hub OK
   Additional picture:	Courtesy of PORSCHE CARS NORTH AMERICA, INC. Wheel hub not OK
   Courtesy of PORSCHE CARS NORTH AMERICA, INC. Wheel hub OK (1)
   Result/Action required
   => The wheel hub  does not  have to be replaced.	=> The wheel hub must  be replaced.

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

   Courtesy of PORSCHE CARS NORTH AMERICA, INC.

   Checking cone ring on central bolt

   Assessment of cone ring on central bolt
   Looks normal and seems normal while driving	Excessive signs of wear
   Wide contact pattern  > Cone ring OK  There is no discoloration on the coating of a new cone ring on the central bolt. After a certain mileage, a grey/black contact pattern forms, with the main pressure point in the center: > Contact pattern width: approx. 10 mm + 5 mm -Arrows-  . The complete surface is blackened on vehicles with high mileage.	Narrow line  > Cone ring not OK  Only a narrow line can be seen on the small diameter of the cone ring on the central bolt -Arrow-  .
   Courtesy of PORSCHE CARS NORTH AMERICA, INC. Cone ring OK
   Additional picture:	Courtesy of PORSCHE CARS NORTH AMERICA, INC. Conering not OK
   Courtesy of PORSCHE CARS NORTH AMERICA, INC. Cone ring OK  (1)
   Result/Action required
   => The wheel hub  does not  have to be replaced.	=> The wheel hub must  be replaced

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

   Courtesy of PORSCHE CARS NORTH AMERICA, INC.

   Checking wheel cone

   Wheel cone assessment
   Looks normal and seems normal while driving	Excessive signs of wear
   Wide contact pattern  > Wheel cone OK  After a certain mileage, an even contact pattern forms on the wheel cone: > Contact pattern width 10 mm + 5 mm	Narrow contact pattern  > Wheel cone not OK
   Arrows-  . At first, this is just a shimmering surface, but the surface turns completely black on vehicles with higher mileage.	Narrow (linear) contact pattern that is uneven or only in spots -Arrows-  .
   Courtesy of PORSCHE CARS NORTH AMERICA, INC. Wheel cone OK	Courtesy of PORSCHE CARS NORTH AMERICA, INC. Wheel cone not OK
   Result/Action required
   => The wheel hub does not have to be replaced.	=> The wheel hub must be replaced. Checking the wheel cone is only an indirect way of checking the wheel hub. The actual wheel  does not  need to be replaced if the wheel cone looks like this.