Retainer nut. A Nut used to retain the Diesel Exhaust Fluid (DEF) Tank to it's mounting point. A solid metal or plastic block with a threaded hole in the center which is used to tighten or adjust the Fuel Tank Skid Plate. Fuel Tank Strap Nut. Part cannot be reused/reinstalled. Spare Tire Nut. Suspension Stabilizer Bar Link Nut. Adjusting Screw. Diesel Emissions Fluid (DEF) Tank. Diesel Exhaust Fluid (DEF) Tank. Fuel Tank Strap. Retainer. Skid Plate U -. Spacer. Spare Tire retnr U -. Suspension Stabilizer Bar Link. Suspension Sway Bar Link.