Our driver's side tow-hook was a short lived experience. I dropped down down two bolts from the hole above and used standard lock washers on the outside/lower holding the hook in place. However, in a very short time I caught the hook, doubled it back and had to remove it. I did not use a lock washer inside the frame.

All in all, once I decided to drop the bolt in rather than try to locate the nut & washer on the inside it was a very easy task.