My thoughts lean to - - only one motor driving two legs might cause a bind - If that is your situation. I like the idea of lube. I run the legs to FULL hight - block the frame - then do the LUBE JOB. and then run the legs up and down several times - - with NO weight on the legs. You guys have GOOD IDEAS. Once a year might be enough. I have ALSO BROKEN the main lower/raise screw - may have been due to poor material I WAS able to REDRILL the shaft and install a new bolt.
NOW - any NEW trailer ( have had 4) BEFORE I use the unit I re-drill the screw holes and use a Grade 8 hardened bolts in US and NOT metric size to replace, !/4/ inch as I recall I also use washers to take up ANY slack in the unit - Like who ever heard of a square tube on a round shaft, the spacer washers take up ANY SLACK - NOW when I hit the Raise/Lower button it engages RIGHT AWAY - with NO DELAY of the round shaft taking up slack on the square shaft.
I hope this sounds what I mean.
Easy peasy - about 1 hr work - cured forever.