My directions called for the bolt to be tightened 1/4 turn past touching. From the way I understand it, the downward pressure and friction hold the bracket in place. Mine have never moved, even with some tight maneuvering.
1998 Jayco Eagle 302FK (Honda EU3000is)
2016 GMC Sierra Denali 3500HD 4x4 Duramax/Allison
2003 Honda Aquatrax F-12X Turbo