1. Clean the encoder or pulser, and make sure no metal is stuck to the encoder surface. Check the magnetic encoder (A) or pulser (B). If cracked or damage, replace the encoder or pulser. Front wheel bearing replacement Rear hub bearing unit replacement Measure the air gap between the wheel sensor (C) and the magnetic encoder and pulser all the way around while rotating the encoder or pulser.
   Standard:
   | Front: | 0.5−1.2 mm (0.02−0.05 in.)
   | Rear: | 0.4−1.1 mm (0.02−0.04 in.)
| Front Rear