Raise and support vehicle, then remove rear wheel and grease cap.
While rotating brake drum, torque locknut to 18-22 ft. Lbs.
Loosen locknut until it can be turned by hand, then measure seal drag as follows: Install a lug nut onto brake drum and place nut at 12 o'clock position.
Using an inch lb. Torque wrench, measure amount of force needed to start rotation of drum. Record seal drag measurement.
To determine specified preload, add seal drag measurement recorded in previous step to required bearing preload of 1.3-4.3 inch lbs.
Tighten locknut slightly, then measure amount of force needed to start rotation of drum.
Continue to tighten locknut until preload determined in step 4 is reached.
After adjustment is completed, stake locknut to spindle with rounded chisel. If splitting or cracking occurs after staking, replace locknut.
Install grease cap and rear wheel, then lower vehicle.