When you are trying to knock out a rock golem, have a paracer with some sort of cannon on the back of it put that futher back away from the rock elemental and start to place pillars in between you and the rock elemental. Get its attention and try to run avoid its attacks and get on the turret while it's attacking the pillars and fire away at its head!!
For some reason, after the latest update, X-rock elementals (haven't checked other variants) are no longer tameable. Whenever you knock them out, they don't eat and don't have a taming bar. Forcetame also doesn't affect them, so I believe it's a glitch
To tame these turret soakers I’d recommend getting four metal gates 5 pillars 3 ceilings and 3 walls. For the trap and the pillars are supposed to prevent the golems rocks from hitting the cannon. AIM FOR THE HEAD