On all 1964-68 series, the normal end play in a front-wheel hub can mistakenly be interpreted as loose wheel bearings. This error arises because the wheel bearings have an end play of .002 to .006 in. when they are properly adjusted, and the adjusting nut can be turned with the fingers. If the nut is tightened to eliminate all end play, early failure of the bearing can result.
To adjust front wheel bearings on 1964-68 models, first torque the spindle nut to 19 lb.-ft. while rotating the wheel. This seats the bearings. Then back off until the bearings are loose, and retorque to 11 lb.ft.
If the hole in the spindle now lines up with one of the six slots in the nut, backoff one slot and install the cotter pin. Where the hole and a slot do not line up, back off the nut not more than one-sixth turn until the hole and a slot are in line.