I keep a spray can of white lithium grease in the back of the truck and give both the ball and the spring bars a quick spray when hooking up. White lithium grease is used on farm quipment and on motorcycle chains because it doesn't collect dirt and grit. It quickly gets a dry film on the surface but retains the lubricating quality. I buy it at Tractor Supply here in Dripping Springs.
John W. Irwin
2005 Classic 28 "Sabre-Dog III"
2013 Silverado 2500HD Duramax/Allison LTZ
WBCCI #9632, TAC TX-10