LOCK CYLINDERS, DOOR HINGES AND HINGE CHECKS
GM recommends their Multi-Purpose Lubricant, Super-Lube, part no. 12346241, or equivalent general purpose silicone lubricant. Apply any lock lubricant sparingly.
HOOD LATCH, PIVOTS, SPRING ANCHOR AND RELEASE PAWL
Use Lubriplate® brand lubricant in an aerosol container, GM Part Number 12346293, or equivalent. This type of NLGI #2 lubricant is commonly referred to as "white grease" and is a relatively thin grease. It is also available in small cans and can be applied with a brush.
Apply a thin coating of Dielectric Silicone Grease GM Part Number 12345579, or equivalent. Apply sparingly and buff with a soft, dry cloth.
Use plain water to flush any corrosive materials (road salt, etc.) from the underbody. Take care to clean thoroughly any area where mud and other debris can collect. Check that any drain holes in the doors and rocker panels are open. Use a small screwdriver to clear them of any debris.