Operation CHARM: Car repair manuals for everyone.

Gear Tooth Nomenclature

GENERAL INFORMATION





The side of the ring gear tooth which curves outward, or is convex, is referred to as the "drive" side (4). The concave side is the "coast" side (3). The end of the tooth nearest the center of ring gear is referred to as the "toe" end (2). The end of the tooth farthest away from the center is the "heel" end (1). The toe end of the tooth is smaller than the heel end.

TEST
1. Wipe oil out of axle housing and carefully clean each tooth of the ring gear.
2. Apply gear marking compound sparingly to all ring gear teeth using a medium stiff brush.
3. Use the service brake to apply a load until a torque of 54-68 Nm (40-50 ft. lbs.) is required to turn the pinion.

A test made without loading the gears will not give a satisfactory pattern. Turn the companion flange with a wrench so that the ring gear rotates one full revolution. Then reverse the rotation so that the ring gear rotates one revolution in the opposite direction. Excessive turning of the ring gear is not recommended.





4. Observe the pattern on the ring gear teeth and compare with the image.