Jacks on our 310GK seemed to be binding a bit. When they were operated they would often seem to have to "break free" from something gripping them before they started moving, not smooth.

Somewhere on this forum I read advice about adding anti-stiction fluid to the hydraulic system. Works beautifully; jacks are noticeably smoother, no gripping / lurching / binding noise after only a couple of cycles of the hydraulics. Sorry that I can't find that thread to say thanks.

Here's the link to LCI's instructions for doing it.

https://www.lci1.com/images/support/lipsheet/0295.pdf

Somewhere along the way I picked up the advice to ONLY buy the CAT fluid, not the other brands. I did, works a charm.