Pretty much all you do with an Aventa II is wash it with soap and water. Take it from me and the Blue Ox instructions, NEVER,EVER lube the pivot ball on an aventa. You can lube the joint where the arms are mounted with silicone about once a year.
I just had mine serviced by Blue Ox at the Perry, Ga. FMCA rally. The tech told me that they suggest a service kit around 10K miles, but mine has 20K and really didn't need the kit. They did it anyway and all is good. Make sure the arms don't have a lot of play when fully extended at the point where one tube enters the other. If they develop serious play here it's time to replace the arms. As long as the pivot ball stays tight then it's good, if it gets loose or sloppy the service kit comes with shims to tighten it back up.
Pretty much the service kit has shims for the ball pivot if needed and new teflon washers for the arms where they mount to the ball pivot and new teflon washers for the triple lugs where they mount on the ends of the arms. Other than installing this a factory service amounted to cutting the zip ties on the accordian rubber gaurds, cleaning the extende arms under the accordian, then greasing them with a brush and bearing grease. After that you install new zipties on the boots and your done.
One other thing the Blue Ox rep talked about at a seminar. If your bar has remained in the reciever for a lot of miles pull it out. The hole for the reciever pin can wallow out as the bar works back and forth under load causing a burr around the hole in the bar. If left unchecked long enough the burr can become severe enough to hang the bar up in the reciever. Burnish the burr off of the bar with a file if one exists and then re-install the bar in the reciever.
Hope this all makes sense.
2007 Newmar Kountry Star 3914, ISL400
2001 Jeep Cherokee toad, M&G brake/2011 Jeep Grand Cherokee Overland