I recently bought a 8417 Bison living quarters trailer with a 12ft slide and was having some trouble with the trailer bumping or bucking the truck while I was driving or stopping. I have a ford dually with air bags and had pulled a bigger living quarters trailer previously without problems. The Bison's wheels are positioned further forward under the stud stall and 2nd horse making it less balanced causing the bump or the buck to the truck (believe me it was rough). I bought a Shocker Hitch to smooth the ride out and man it really works taking I would say 90% of the bump and buck out. I run 40psi with 3 horses and 50 psi with 4 horses and it works great I started at 25psi and worked my way up. I posted this for 2 reason I couldn't find any review with my problems and nobody talked about the pressures they run with it. I hope this helps some people thanks.