In areas of the country where there was snow, salt, or even dirt roads the AD trucks were very prone to the frames rusting away, usually just in front of or in the area around the front hanger of the rear springs. Many were repaired with plating and a number were repaired by grafting on a good frame section. The latter was definitely better and as far as I can remember they gave no problem, even when returned to heavy duty use as a truck. I think the mild steel they used as opposed to the high carbon modern frames with "Do Not Weld" stickers was suited to this type repair.
