Originally Posted by
Duragrouch
Heavy trucks that use flat-seat lugs still have left-left lugs, and even some with taper seats just to be on the safe side, in case non-taper wheels are mounted. Close-fit hub-piloting wheels also help.
Stud piloted dual truck wheels that used inner cones and outer nuts and ball seats had left hand threads on the left side of the vehicle.
Those gave way to hub piloted wheels in the late 80s. All right hand threads, no ball seats, and nuts with bell washers. One set of nuts secures both inner and outer wheel. No inner cone to secure the inside wheel first.
Of course, I refer to American units. Things may be done differently elsewhere.