Dually swing out Jack not locking into position?

Mine do that. I just push down on the top and then wiggle the jack at the same time and it works into place. I was told once to pull the pin and scrub it with brake fluid getting off the rust. I then lubed it with WD 40. That worked but it started doing it again in a couple of months and found the wiggling worked fine, so I have just stayed with that.