The GrassGator heads require a threaded shaft that's about an inch long for installation.
Curved Shaft trimmers have a long shaft (about 2" long) that can't be removed. That's too long to install the GrassGator head by itself so we use your trimmer's original spool housing and the spacer cup included in the kit to take care of the extra space.
The following instructions are for trimmers, curved, straight, electric, or battery-operated that come with a threaded shaft 2" or longer. Not all curved shafts install this way and some straight shafts may follow these instructions.
You can check the Brands section to see if your particular brand and model follows these instructions.
Curved shaft trimmers with fixed line heads follow the Fixed Line instructions.
All our replacement heads follow the same basic set of instructions. There are a few GrassGator models that require some extra steps. Follow the instructions below regardless of the GrassGator head you are trying to install. If your GrassGator head requires additional steps then you will be prompted to click on a new link once you have reached that stage of the installation process.
* From this point forward we'll use the term "curved shaft" for any trimmer, straight or curved, that follows these instructions.
* Your trimmer may not look exactly as the ones illustrated. We used different trimmers on the pictures for clarity purposes.
* Your GrassGator head may be a different model than the one illustrated but it will still follow the same instructions.
Check our "Brands" section to see if your model follows these instructions
Remove the bottom part of the housing. Some trimmers have tabs that you push toward the head to open it up. On some others, you unscrew the bump knob.
Remove the spool, any remaining line, and the spring.
Leave the spool housing on (the top that's attached to the trimmer) . This will prevent the spacer cup (installed ont the next step) from sliding all the way down the shaft.
Slide the spacer cup over the shaft, close side facing out. This will take care of the space inside the spool housing while giving the GrassGator a flat surface to sit against.
Next, find the correct fastener. The GrassGator kit comes with a pack of 7 nuts and 2 bolts. Most curved trimmers have a shaft that's threaded on the inside (female). Very few have a shaft that is threaded on the outside (like the picture on the left). If the shaft of your trimmer is threaded on the inside then find the bolt from the kit that fits the shaft. If the shaft is threaded on the outside then find the nut that fits the shaft. Most curved shafts require a regular right-hand threaded fastener (silver) but in very rare cases, a left-hand thread nut or bolt is needed.
The nuts in the kit may look the same but are in fact all different sizes. Some of them, however, are very close in size so you may find some nuts that start but then seize after a quarter turn. If that happens, don't force it, and try other nuts. For most trimmers, the required nut is included in the kit.
Once you find the correct nut or bolt, set it aside.
First, locate the bottom of the GrassGator head. The bottom of the GrassGator head is the side with the hex-shaped recessed hole. This is the side that should be facing the ground once the GrassGator head is in use.
Very important: The hex-shaped hole on the GrassGator head will NOT go over the hex on the top of the shaft.
The hex hole on the GrassGator head should be facing the ground plus, if you can see the hex nut on the top of the shaft then it means you removed the spool housing. Go back to Step 1 and make sure you leave the spool housing on.
Drop the nut or bolt you found on step 2 inside the hex-shaped recessed hole. The shank of the bolt should go through the hex-shaped hole and the head of the bolt should sit inside it.
On Fixed line heads like the 8010 and 5600, the bottom is the flat round side, not the side that sticks up
On bladed units (3600,4600,4680) and Multi-Tool units (4700 and 5620), the bottom is the flat round side, not the triangle side.
With the nut now inside the hex-shaped recessed hole, slide the GrassGator head over the shaft.
On bladed units, the triangle side goes against the spacer cup, round side with the nut facing out.
On pre-cut line units, the side that sticks up goes against the spacer cup, flat round side facing out.
The GrassGator head will work as a wrench. You may have to start the nut or bolt with your fingers but once the head of the bolt or the nut is inside the hex-shaped hole on the GrassGator head you can then keep turning the GrassGator head until it's tight. There should be no up-and-down play at all. The GrassGator head should be tight against the spacer cup. Any gaps may damage the GrassGator head or your trimmer.
If there's no gap and everything is tight then, you are done and ready to use your new GrassGator!