Those "bearings" which are not really bearings are detents for the connection. Clean and dry is the best recommendation. Any lube used may attract dirt which will make it worse. If it is sticky and won't connect and hold, then use some brake clean to get the junk out of it and try again. Dry lube (as suggested) may help, but that coupling is designed to be lube free. WD40 can help with freeing up a sticky coupler, but I would follow that with brake clean to get the oil off since, again, that will attract dirt. And, it goes without saying, don't store uncovered. I stick my coupler end in a zip lock with a rubber band before tossing into storage. Happy camping.