How to Wind a Trimmer Head

As a STIHL trimmer owner, you will eventually need to replace its trimmer line. STIHL makes a variety of trimmer models, as well as trimmer head styles. Depending on your trimmer head, you will replace your trimmer line differently. Below you will find step-by-step instructions on how to replace trimmer line on four of our most common trimmer head models. For complete instruction on the operation and care of your STIHL trimmer, refer to your product manual.

STEP ONE: Before You Start

The first thing to do before replacing the trimmer line on your STIHL trimmer is to ensure that the trimmer is turned off. If you were recently using the trimmer, its gearbox will be very hot. Wait for the gearbox to cool before handling the trimmer head. Once it is cool, clean the trimmer head with a dry cloth and remove any excess grass clippings or other debris. NOTE: To identify what type of cutting head your STIHL trimmer has, refer to this chart for more information.

STEP TWO: Removing the Trimmer Spool Housing

AutoCut® 25-2: Grasp the body of the spool housing firmly with one hand. With the other hand cupped over the tapping side of the head, insert your thumb into the tab release is located and push firmly down toward the base of the spool housing. This will release the tab. Rotate the head around 180 degrees and repeat the same procedure on the second tab. The cover is now released and you can remove it, along with the spool. You may need to press down on the spool and rotate it slightly for it to release from the spool housing.

AutoCut® C 25-2: Unscrew the spool housing until it is loose and can be removed from the trimmer head.

TrimCut™: Unscrew the star nut on the head. Once the star nut is loose, remove the nut and the spool.

FixCut™: Unscrew the nut on the head. Once the star nut is loose, remove the nut and the spool.

STEP THREE: Clean the Housing

Loosen the cap and lift the spool out of the spool housing. If there is a spring, be cautious not to lose the spring located in the center of the spool. Once the cap and spool have been removed, wipe away and tap out any dirt or debris that has collected inside. NOTE: You do not need to open the head on EasySpool™ cutting head models to rewind the spool, but you can still open it to clean the housing.

STEP FOUR: Wind the Spool

First, you will need to determine what diameter and length of trimmer line is required to wind your spool. This information is found on the instruction card that comes with your STIHL trimmer head. You can also view and download those instructions here.

AutoCut® 25-2: Once you have determined the proper length of line you need, cut two strips of line that length. Inside the spool, there are two identical sets of retaining holes located on opposite sides of the spool. Insert one end of the line into a retaining hole and begin winding in the direction indicated at the bottom of the spool. When you have finished winding, lock the end of the line into a notch located at the top of the spool. Next, wind the other side of the spool, starting on the opposite end of the spool where you started the first. Once finished, lock the line into a notch as well.

AutoCut® C 25-2: First determine the length of trimmer line you will need to properly wind your spool. Then, bring the spool on the trimmer head into the correct position as indicated by the markings on the spool. Insert the tapered ends of the line into the two eyelets. Turn the knob clockwise, winding the line around the spool. Once the line has been fully wound, cut the line.

TrimCut™: Once you have determined the proper length of line you need, cut two strips of line that length. Inside the spool, there are two identical sets of retaining holes located on opposite sides of the spool. Insert one end of the line into a retaining hole and begin winding in the direction indicated at the bottom of the spool. When you have finished winding, lock the end of the line into a notch located at the top of the spool. Next, wind the other side of the spool, starting on the opposite end of the spool where you started the first. Once finished, lock the line into a notch as well.

FixCut™: Push an approximate 8-inches-long piece of line into the eyelet until it can be seen on the inside. Insert a similar piece of line into the second eyelet.

STEP FIVE: Reassemble the Trimmer Head

AutoCut® 25-2: Carefully insert the loaded spool back into the spool housing. Align the spool so that the notches are near the edge of the eyelets located on the spool housing. Press down and rotate the spool until the notches and eyelets line up exactly. Release the spool (it should remain in this position upon release). Gently remove the line from the notches and feed them through the eyelets. Replace the cover, ensuring the tabs snap firmly into place. Pull the line until all the slack is taken up and the spool engages. 

AutoCut® C 25-2: Place the loaded spool housing onto the trimmer head and rotate clockwise to tighten. Pull the line until all the slack is taken up and the spool engages.

TrimCut™: Carefully insert the loaded spool back into the spool housing. You will need to feed the line through the eyelets in the spool housing as you are lowering the spool into place. Pull the line until the line releases from the spool notches. Then, replace the star nut and tighten. Finally, pull the line once more until all the slack is taken up and the spool engages.

FixCut™: Place the loaded spool housing on the trimmer head and replace the tightening nut. Pull the line until all the slack is taken up and the spool engages.

NOTE: Not all STIHL trimmer line is compatible with your STIHL trimmer head. Please refer to your trimmer head instruction card to determine the correct diameter and length of STIHL trimmer line you will need. If you do not have this card, you can download a digital version online at STIHL Product Instruction Manuals