The objective is to achieve proper and consistent bearing adjustment, targeting .001” – .005” of end-play between the spindle and hub.

The components include the spindle, hub with bearing races (cones), bearing cups, oil seal, castle nut, and washers (flat washer, D-washer, tang washer as specified in the BOM for the end unit).

With the spindle secured at the axle mounting end, tighten and torque the castle nut to 450 to 500 inch pounds while rotating or oscillating the hub. Ensure a minimum of three complete rotations of the hub about the spindle to fully seat and align the bearing rollers within the cones and cups.

Loosen the castle nut 1/6 of a turn (one flat or one slot of the castle nut). Check that the hub rotates freely on the spindle without any obvious internal friction. If friction is felt, loosen the castle nut 1/6 of a turn more. Ensure the cotter pin will pass through the castle nut slot and spindle drilling, or that the tang washer is correctly oriented.

Loosen the castle nut a little more until alignment is achieved.

Check end-play by pulling outward on the hub with both hands. There should be no movement detected. If movement is detected, repeat the tightening, loosening, and checking steps.