You really need to do a bit more than just put some lightweight lube on the moving parts periodically. From first hand experience if a Hi-lift gets left out in the weather and you need to use it, make sure everything is mostly broken free (a couple taps with a boot or dead blow hammer works well), then lube LIBERALLY, and work the lube in. Once you think it's worked in make sure visually that everything works correctly - not just looks like it works but it WORKS. If not you can drop your load.
Hi-Lifts are excellent tools, but just like in any recovery, lifting or winching situation there are some heavy loads and forces involved and you have to be careful.