Abstract: A transport lock joint is provided for an implement with a center section and wing sections adapted for stack folding to transport positions over the center section. The lock joint includes an insert element mounted on one of the wing sections and a retainer element mounted on the other wing section. With the implement in its stack-folded transport position, the insert element is received within the retainer element and the wing sections are mutually restrained against relative movement, particularly relative movement associated with the over-the-road travel. Unfolding the implement to a field working position disengages the lock joint by extracting the insert element from the retainer element.