Inspect Gears

• The first procedure in checking the contact of the ring and pinion gear is to inspect the gears for dimples or damage. The gears must also be inspected to determine what machining method was used to mill the gears. The gears will have been milled by face-hobbing or face-milling. Determining which machining method was used to cut the gears determines which contact check procedure or gear pattern chart required to set the contact point.
  
  

Heel Contact

• The heel contact is when the ring gear contacts the pinion on the outside face of the gear. The top heel contact point is when the toe or inside face of the ring gear makes contact with the heel or outside of pinion. This condition causes the gears to wear irregularly and prematurely damages the face of the gears.
  
  

Toe Contact

• The toe contact is when the ring gear makes contact with the pinion on the inside face of the gear. The top toe contact point makes connection with the pinion of the inside, and the ring gear contact point is on the heel or outside of the gear. Again, this causes the gears to wear prematurely and prevents the transfer of all the power available.
  
  

Alignment and Correct Pattern

• Aligning the ring gear and pinion so the contact point of each gear is located at the center is the correct gear pattern. The gears must be positioned for the transfer of all the power available. Wear of each gear will occur normally, and the operation of the drive shaft, axle and wheels will be smooth. When aligning and adjusting the ring gear to the pinion, shims can be used to adjust the contact points when toe contact or heel contact occurs.