I have a great set of Thule racks to put on top of my Syncro and I'm missing a very small wrench or something (not an allen-head) that fits between the interior channel of the tower #1050, and under the rail on a square ny-lock nut that goes on a bolt attached to a plastic triangle. I would appear that as the bolt tightens and entends into the bottom of the rail thus locking it into position?
I have several sets of Yakima but no towers tall enuf for the rear roof line on a vanagon.
I've looked on the web-site and called w/o success to Thule as they seem to know less about their product than I.

signed
Truly Perplexed and Cranky
Bob Allen