GEAR, REDUCTION

551 900 86 GEAR, REDUCTION is what really takes the high-speed input from a hydraulic motor and steps it down, boosting the torque significantly. Think of it as the muscle behind your feed system, rotation head, or even within a tramming gearbox. It's all about getting that grunt to push the bit or turn the rod without burning up the motor or overloading the hydraulics. It converts speed into raw power, letting the rig do the heavy lifting it's designed for, whether you're collaring a hole or pushing through tough rock.

When this gear starts to go, you'll usually notice it first as a change in sound. That smooth hum or steady whir turns into a distinct whine, or sometimes a grinding noise, especially when the system is under load. You might also feel a bit of vibration coming through the feed or rotation unit, or the movement itself could feel a bit 'lumpy' or inconsistent. If it's really worn, you'll often find fine metal flakes in the oil when you drain it, or the oil might just look darker and have a burnt smell, indicating excessive friction and heat.

Replacing one of these isn't usually a quick job, so you want to make sure you're doing it right the first time. Always take the opportunity to thoroughly check the mating gears and shafts for any signs of wear, pitting, or damage while you're in there. A common mistake I’ve seen is folks just swapping out the worn gear without really looking at the bearings it runs on. Those bearings are absolutely critical; if they're shot, the new gear won't last long either. And for crying out loud, use the correct type and amount of gear oil; it makes a huge difference to the longevity and performance of the whole assembly.