Grease Your String Trimmer's Gear Head Before It Overheats

The Problem

The gear head at the business end of a straight-shaft string trimmer — the angled housing the cutting head bolts to — is full of gears that came greased from the factory and have been running that grease out ever since. Nobody services it because nobody knows it's serviceable. This creator found out when his got hot enough that he thought it was about to catch fire mid-job.

The Technique

There's a small screw on the gear housing that most people assume is structural. It's a grease port.

1. Buy trimmer gear-head grease — hardware stores sell it in a squeeze tube with a threaded nozzle made for exactly this port.
2. Remove the port screw on the gear housing.
3. Thread the tube onto the open port.
4. Squeeze grease in while slowly rotating the cutting head by hand, so the gears carry it around the housing instead of packing it into one spot.
5. Reinstall the screw and wipe the excess.

Once a season is plenty for homeowner use. The whole job takes two minutes and the tube lasts years.