Lateral Runout

Lateral runout is the movement of the rotor from side to side as it rotates on the spindle. This could also be referred to as "rotor wobble". This movement causes the brake pad and piston to be knocked back into its bore. This condition results in additional pedal travel and a vibration during braking.

Figure 1 (2WD Model Pictured):

Inspecting for Lateral Runout (see Figure 1)
1. Install tool J 37620 on K1, K2 trucks to provide clamp load to simulate "as installed" conditions.

2. Adjust the wheel bearings to eliminate all freeplay (2 wheel drive only).

3. Attach a dial indicator to some portion of the suspension.

^ The point of the stylus must contact the rotor face about 25 mm (1-inch) from the edge of the rotor.

4. Turn the rotor one complete rotation.

^ The lateral runout should not exceed 0.13 mm (0.005-inch)

5. Readjust the wheel bearings, refer to section 3C of the appropriate service manual (2 wheel drive only).