Adjusting the bearing preload

update , so looks like the PO did one side and not the other somewhere along the line , both drums are different makes , one is 1 m.m. smaller where the brake shoes touch, one side has timken outer bearing made in the us , the other side has national made in mexico, although they do have the same numbers on them , both have national wheel seals , so I guess the inners are also national . I always thought that you never did one side only?