WD Hitch (3rd chain link or 4th chain link)

You need a min. of 5 links under tension so that the hanger brackets or spring bars won't hit the A-frame. If you have over-slung axles (axles above springs), the A-frame will be closer to the ground and you will need fewer links under tension, but not less than 5. One set of Reese instructions for the round bar version says: "If there are less than 5 links between hook and u-bolt adjust ballmount angle rearward, and repeat procedure - see Fig. 3 & 4 below" Reese's instructions are not the greatest and they have different ones for '09 and earlier and '10 and later.

The best thing you can do is go to the towing forum and there is a sticky at the very top that goes into a lot of detail and discussion on the Reese DC hitches.