Sliding sub-frame for heavy-duty vehicle suspension, including torque box, air slider pin, and shear-off nut

An air sliding-pin system for a sliding sub-frame of a heavy-duty vehicle suspension, comprising:

• a mounting bracket adapted to be affixed to a sliding sub-frame and having an outer sidewall adapted to slide by an underhung track of a vehicle frame;
• a sliding pin extending from a shaft at a transition, the sliding pin and shaft reciprocating between an engaged (outer) extreme and retracted (inner) extreme, wherein the shaft has a smaller diameter than the sliding pin, and the transition represents an inner-facing shoulder;
• the sidewall having an aperture for the sliding pin to extend out of and retract inside of as well as being adapted to register with location holes in the underhung track of the vehicle frame;
• the mounting bracket presenting an inner sidewall with an aperture sized for the shaft to reciprocate therein;
• a coil-compression spring inserted over the shaft and confined between (1) an inner-facing shoulder of the sliding-pin to shaft transition and (2) an outer surface of the inner sidewall of the mounting bracket;
• a reciprocating yoke having spaced arms reaching around the inner sidewall from inboard of the inner sidewall and coupled to either or both of the shaft or the sliding pin, said spaced arms flanking and joined together by a web;
• a gas assist bladder disposed between (1) an inner surface of the inner sidewall of the mounting bracket and (2) the web of the reciprocating yoke;
• and
• a source of pressurized gas for the gas assist bladder whereby inflation of the gas assist bladder pushes the yoke inwards and pulls the sliding pin inside, and, deflation of the gas assist bladder allows the coil-compression spring to push on the inner-facing shoulder and push the sliding pin out.