Hensley doesn't recommend removing the caps. I was told the bearings should never need to be repacked and was advised against doing so.
Something that does wear and should be checked for too much play are the bushing sleeves that the bars slide into. If you have the bars hanging loose and pull up on them do they have a lot of play before they engage? If so, they should be replaced. I didn't realize mine were bad until I noticed a weld holding the sleeves together had broken, warranting a replacement bushing. Now the bars are snug in the bushings with very little play.I think replacements are around $45.