Very common problem.. Anyone who owns an 2006 and up F53 will most likely experience the same issue. If it isn't caught, the bolts either loosen up and fall out and/or break the torsion bar mount.
Used blue locktite and torqued them to 65 ft lbs..
Keep an eye on them.
1999 Fleetwood Southwind 35S (Ford F53 6.8L V10 275hp 4R100 4 spd trans) - Toad 2003 Saturn Vue.
It won't do MACH 2, but I can get a sandwich and take a pee.