There are two points of contact for the bars. One you lightly lube; one you don't. It's important to know the difference unless you want to go out of the manufacturer's instructions.
The install manual can be found online:
Under maintenance for the lift bracket (part#24) it states:
"Keep lift brackets clean, and using a light lubrication on the lift bracket support surfaces to keep rust to a minimum is acceptable."
Regarding the top and lower plates (parts #1 & 2):
"Do not apply lubrication to the friction surfaces of the top and bottom plates
or on the top or bottom trunnion surfaces as this will reduce the built in friction sway feature."
I follow these instructions and find the hitch to work effectively without being noisey.
Also, jacking the TV and trailer up so that the bars are within an inch of the plates makes installing them (or taking them off) much easier.
According to the manual:
"If it is too difficult to lift the spring bar, then raise the height of the trailer until the spring bar is closer or vertically to the spring bar support surface of the lift bracket."