Genuine Top Tuning spare/option part. Motor pinion made of nitrided hardened steel, module 1.5 and 8 mm bore. Reinforced hub for set screw M5x6. The pinions with odd tooth counts are profile shifted. Within the same outer diameter, there is no need to adjust the backlash when changing the pinion. When mounting on vehicles with mounting holes in the motor mount that are specific to the tooth count, the mounting holes for the higher number of teeth in each case (16 or 18) must be used.Profile regraded:This means that the number of teeth is changed while the diameter remained constant. The part of the involute curve that defines the tooth profile is changed. Positively regraded (lower number of teeth) pinions are stronger and run smoother, the reduced strength of negatively regraded pinions doesn´t really matter. Available in two sizes with two tooth counts:Outer diameter 30 mm with 17T or 18TOuter diameter 27 mm with 15T or 16TContents:1 piece