Removing the head from a weed eater, whether for line replacement, deep cleaning, or upgrading the cutting apparatus, involves disconnecting it from the drive shaft. This connection is engineered to withstand high rotational forces without loosening during normal operation. Understanding the specific locking mechanism and thread direction makes this a straightforward procedure.
Essential Preparation and Safety
Prioritizing safety is the first step before attempting any maintenance on a power tool. For electric models, unplug the power cord or remove the battery pack entirely to eliminate accidental activation. If you are working with a gas-powered weed eater, the engine must be completely off, and the spark plug wire should be disconnected from the plug.
Once the power source is secured, gather the necessary tools, which typically include a small rod, Allen wrench, or screwdriver to act as a locking pin. Clean the area immediately surrounding the head attachment point. Removing built-up grass clippings, dirt, and solidified sap will expose any small bolts, nuts, or the crucial locking hole that facilitate removal.
Step-by-Step Head Removal Process
The removal process begins by immobilizing the drive shaft to counteract the torque applied when unscrewing the head. Most trimmer housing designs include a small hole near the base of the head attachment point. Rotate the head by hand until an internal hole in the shaft or gear mechanism aligns with this external access point.
Once aligned, insert your small rod or dedicated locking pin into the hole, which effectively locks the shaft and prevents it from spinning. With the shaft securely locked, the head can be unscrewed. You must first determine the correct rotation, as most weed eater heads use a reverse thread.
To loosen the head, you must turn it clockwise, or to the right, which is the opposite of the standard “righty-tighty, lefty-loosey” rule. For heads that are bolted on, use a wrench or socket to unscrew the exposed nut. Otherwise, apply firm, steady clockwise pressure to the entire head until the threads disengage. Once the head is free from the shaft, gently slide it off, taking care to observe the order of any washers or spacers, as these components are necessary for proper reinstallation and balance.
Troubleshooting Stuck Heads and Final Tips
If the head has seized onto the shaft due to rust, corrosion, or compacted debris, apply a penetrating oil directly onto the threaded connection point and allow it to soak for 15 minutes to break down the bond. If the head resists moderate twisting force, a light, sharp tap with a rubber mallet around the perimeter of the head can help shock the threads loose. This must be done cautiously to avoid cracking the plastic housing.
If the internal locking mechanism is stripped or inaccessible, secure the shaft further up the trimmer with a pair of vise grips. Clamp only on the metal shaft and protect the surface with a cloth.
Once the old head is removed, inspect the threads on the drive shaft for any remaining debris or damage. Clean them thoroughly with a wire brush to ensure smooth reinstallation. When installing the replacement head, thread it on counter-clockwise (left) and tighten it only until it is hand-tight. Over-tightening can cause it to seize the next time you need to remove it.