Here is a cut/paste from the manual from the year 2000. They may very well have changed it since then.
MAINTENANCE:
9. DO NOT GREASE THE CAM AND CAM ARMS. The Dual Ca
m was designed to use metal-to-metal friction. Heavy
greasing of the cam and cam arm surfaces with affect
performance. If noise is offensive, a very light coating of
lubricant, such as Vaseline, may be used. Tongue weights over 1,200 lbs. may require a light coating of grease to
reduce friction and prevent excessive wear.
10. Check for excessive wear on any contact surfaces and replace if necessary.
