JACK

550 155 73 JACK is typically one of the hydraulic cylinders that helps level the rig or positions the feed beam. It’s a workhorse, really, responsible for lifting and holding some serious weight, making sure the whole setup is stable and square before you even think about putting steel to rock. You'll find it taking the brunt of the load when you're setting up on uneven ground or getting the mast into the right angle for drilling.

When this JACK starts to wear out, you’ll usually notice the rig isn't holding its level like it should, or maybe the feed beam drifts a bit when it's supposed to be locked solid. Sometimes you'll hear a groan or a shudder when it's under load, which is a pretty good sign the internal seals are shot or the cylinder bore itself is getting scored. If it's really bad, you might even see some oil weeping around the rod or the cap end, and then you've got a real problem on your hands that needs attention fast.

Replacing one of these isn't usually a huge job, but you definitely want to make sure the mounting points are clean and not wallowed out from previous failures or vibration. Always check the hydraulic lines and fittings for any signs of fatigue or damage while you're in there; it's easy to overlook a stiff line that's about to crack. And don't forget to properly bleed the system after installation – trapped air can cause all sorts of weird, sluggish behavior.