The tubes enclose the actual working parts. Whatever you decide to lubricate that's exposed to the elements,never use anything oily or greasy. It will attract and hold road grit and dirt, when combined with the greasy lubricant, you just made a crude grinding compound.
Dry-Slide, Moly-lube, and host of other "dry lubricants" are sold for this application.
2000 Winnebago Ultimate Freedom USQ40JD
, ISC 8.3 Cummins 350, Spartan MM Chassis. USA 1SG, retired;PPA,Good Sam Life member."We the people are the rightful masters of both the Congress and the Courts - not to overthrow the Constitution but to overthrow men who pervert theConstitution. "Abraham Lincoln"