The design of the top mounting U-bolt is (was on mine) a major design problem "in my opinion". That U-bolt mounts over a large nut that holds the axle A-frame to the rest of the suspension.
On my unit, a P-30, the nut only only was about 3/4" high. A round U-bolt being mounted to a flange on that short of a nut, seamed an invite to disaster. Where the U-bolt was meant to grip a nut, it should have least been flat or the kit should have included a bracket that went under the nut to prevent it from pulling off.
Any road vibration or large pothole could cause the unit to shift and come loose. I agree with others above. Check the mounting often, and for sure check the top mounting U-bolts! Even a slight misalignment of the cast frame could cause the U-bolt to be torqued enough to pull up and over the bolt.
Travel Supreme: 36' 5er, 3 slides as lake cabin w/all the lake-side toys.