SWING

313 663 98 SWING is usually the big ring gear or bearing that lets your boom or superstructure swing around on the chassis. It’s what carries the whole load – the boom, the feed, the drill string – as you position the rig for the next hole. Basically, it’s the pivot point, taking all that vertical weight and the side forces when you’re swinging the boom out or pulling it back in. Without it, nothing moves, or at least, nothing moves without a whole lot of grinding and groaning.

When this thing starts to go, you’ll usually notice a few things. First off, you might hear some groaning or grinding noises when you’re SWING the boom, especially under load. That’s the rollers or balls inside wearing down, or the gear teeth getting chewed up. You might also start seeing excessive play or 'slop' in the boom movement, where it feels loose or drifts a bit after you stop SWING. Sometimes, it can even cause the SWING motor to work harder, leading to higher hydraulic pressures or slower, sluggish movement. Don't ignore it, because once it really starts to fail, things can get ugly fast.

When you're replacing one of these, make sure you get the mounting surface absolutely clean and flat. Any debris or unevenness will just put stress on the new bearing and shorten its life. And don't forget to check all the mounting bolts – not just for tightness, but for any signs of stretching or damage. It's amazing how many times I've seen a new SWING bearing fail prematurely because a few mounting bolts weren't torqued correctly or were reused when they shouldn't have been. Also, proper lubrication is key, obviously, but sometimes folks forget to cycle the boom through its full range of motion while greasing to ensure even distribution.