I've also looked at a 2006 Cardinal 33 footer and saw the same gap between the nuts. I tend to agree it's for allowance and tollerance. It appears the design of the hardware isn't exactly precision fit.
Met with the owners again and connected the truck batteries to the trailer, plugged it in and cycled the slides. Lo and behold all of them went out and in just like you'd expect.
In fact, twice the two large rear slides would retracted almost at the same time. No jerking or inching at all. The owner looked at me and said he would have never guessed the current from a good battery would have made that much difference. Me too.
Jim - I looked for frame cracks around each wheel. Even scatched the paint in a couple spots if it looked irregular. The owner probably was wondering what the heck I was doing. Didn't find anything.
Tires need to be replaced. Saw some craking on the sidewalls and the owner said they are at least 5 years old.
This deal just might go thru.