Febi Bilstein Ball Joint ProKit - 01791 - Fits VW Front Axle - German OE Quality. This product is designed to be used as originally intended and not modified for purpose. Please ensure the products are installed by a competent individual. Products are usually supplied without fitting instructions. Ball Joint Upper 01791 Febi. Brand: Febi. Part Number: 01791. Placement on Vehicle: Upper Front Axle. Steering arm type: for control arm. Paired article numbers: 01792. Weight: 0.300 kg. Cone Size: 13.8 mm. Note: Observe service information. Extra Description: ProKit. External Thread Size: M12 x 1,5. Type: Ball Joint. To help free moving parts run effectively, bearings are used. A ball joint is theoretically a bearing in a protected steel casing. The bearing stud itself is tapered and threaded offering it to be connected to the steering knuckles and control arms. General road use on today’s roads can cause great impact.