Stihl Trimmer Head Won’t Come Off: How to Fix?

Stihl Trimmer Head Won’t Come Off: How to Fix?

Is there a Stihl trimmer head that you can’t seem to remove? You don’t need to worry, there are several steps that you can take to troubleshoot the issue. This blog post will go over exactly what you should do when your Stihl trimmer head won’t come off and how to fix it. Whether your trimmer is electric or gas powered, these tips and tricks will guide you towards success in solving this common problem. Read on for information regarding how to check whether the parts of the machine are working properly as well as instructions on how to disassemble it safely!

Causes of Stihl Trimmer Head Getting Stuck

Dirt and Grime Buildup

It is not uncommon for dirt and grime to build up around the trimmer head on a Stihl trimmer, making it difficult to remove. This build-up can come from various sources, such as grass clippings or other debris that has become lodged in the head.

Improper Installation

If your Stihl trimmer head was not correctly aligned when you installed it, then it may have become stuck after use due to friction between the internal components of the engine. [1]

Damaged Components

If the trimmer head won’t come off, there may be a problem with the components of the head. Check for any damage to the internal parts, such as the spool, nut, or spring. If any of these components are broken or damaged, they will need to be replaced in order for the trimmer head to work properly again. Once you have identified any damaged components, it is recommended that you take your trimmer to an authorized service center. This will ensure that all parts are correctly replaced and that your trimmer is functioning as intended. Make sure to check customer reviews before selecting a service center so that you can get quality repairs for your machine.

Damaged Components

Using Wrong Tools

Another reason why your Stihl trimmer head may not be coming off is that you are using the wrong tools. When trying to remove a trimmer head, make sure that you are using the appropriate wrench or screwdriver for the job. Using the wrong tool could result in further damage to your trimmer and cause the head to become stuck even more firmly in place. For best results, it is recommended that you consult your owner’s manual before attempting any repairs on your machine.

How To Troubleshoot the Stuck Trimmer Head?

Damaged Clutch

The most common cause of a trimmer head that won’t come off is a damaged clutch. When the clutch wears out, it can become stuck and be difficult to remove. To troubleshoot this issue first check for signs of wear or damage on the clutch itself. If you find any, then you may need to replace the entire clutch assembly before attempting to remove the trimmer head. [2]

Stuck Nut/Bolts

Sometimes nuts and bolts can become stuck due to corrosion or dirt build up over time. This will make it difficult to unscrew them with normal tools. To remedy this situation, try soaking the part in penetrating oil overnight and then use an impact wrench or socket set to loosen the nut/bolt from its thread.

Faulty Trimmer Head

If the trimmer head is faulty or damaged, it can be difficult to remove due to the shape of the part. If this is the case, then you’ll need to use a hacksaw or angle grinder to cut through any stubborn material that may have fused itself onto the trimmer head. Be sure to take extra precautions with these tools as they can cause damage if mishandled. Once the trimmer head has been successfully removed, replace it with a new one before continuing your work.

Faulty Trimmer Head

Damaged Drive Shaft

If your trimmer head refuses to come off despite the removal of the nut, it could be because the drive shaft has become damaged. A damaged drive shaft is a sign that you need to replace or repair the trimmer head. If the shaft is bent or cracked, it may not be able to turn and facilitate the removal of the trimmer head.

Gearbox Failure

In some cases, the drive shaft isn’t damaged but rather the gearbox has failed to function properly. If this is the case, you’ll need to replace or repair the gearbox in order for it to work correctly and allow the trimmer head to be removed. This can often be a more difficult fix than just replacing a damaged drive shaft.

Unscrewing with Pliers

If neither of these options seems applicable, then try unscrewing the trimmer head with pliers. Apply firm pressure while turning counterclockwise until it comes loose. Be careful not to apply too much force as this could further damage your trimmer head. After you remove it, make sure that all components are working before reattaching it. [3]
If your Stihl trimmer head still won’t come off after trying the above steps, you may need to inspect and possibly replace the throttle cable. A damaged or frayed throttle cable can cause tension on the spool, making it difficult to remove. To check the condition of your throttle cable, locate the end where it connects to your trimmer handle and give it a gentle tug. If any of the plastic strands are broken or if there is visible damage, replacing this part may be necessary.

Unscrewing with Pliers

To remove the old cable:

  1. Unscrew all screws that hold together the throttle control assembly with an appropriate screwdriver.
  2. Disconnect both ends of the old cables from their respective locations.
  3. Install the new throttle cable, reconnecting both ends and screwing back together the throttle control assembly with the appropriate screwdriver.
  4. Test to ensure that the replacement cable is properly installed and functioning correctly by attempting to remove your trimmer head again.

Broken Shaft Housing

If the shaft housing of your Stihl trimmer head is broken, then it won’t be able to detach from the motor. First, you should inspect the end of the trimmer for signs of damage. If there are cracks or other signs of wear and tear, then you will need to replace the entire unit. Fortunately, Stihl makes a variety of replacement parts for their trimmers.

You can purchase a new shaft housing from an authorized dealer or online retailer in order to get your trimmer up and running again. To install it properly, make sure that all the screws and nuts are tightened securely before use. If you have difficulty removing the old shaft housing, try using some penetrating oil to help loosen the parts. [4]

Broken Shaft Housing

How Do You Remove A Stuck Bump Knob?

If the bump knob of your Stihl trimmer head is stuck and won’t come off, you may need to take some extra steps in order to free it up. The first step is to inspect the outside of the trimmer head for any corrosion or damage that could be causing the issue. If there is no visible damage, then you can try a few different methods to remove it.

One way to remove a stuck bump knob is by using needle-nose pliers. Place the pliers around the knob, and gently pull outward while wiggling it back and forth. Be sure not to apply too much pressure in order to avoid breaking or damaging anything else on your Stihl trimmer head. Additionally, using a lubricant such as WD-40 or some type of penetrating oil may help to loosen the grip of the knob on the trimmer head. Apply the lubricant liberally around the area and wait a few minutes before attempting to remove it again.

If none of these methods work, then you may need to use some brute force in order to get it off. This should be done as a last resort because there is always the chance that you could damage the trimmer head while trying to remove it. Use a hammer and chisel (or any other appropriate tool) and gently tap around the edges of the knob until it breaks free from its stuck position. Again, be sure not to apply too much pressure when doing this so you don’t accidentally damage the trimmer head.

Once you have successfully removed the bump knob, be sure to inspect it for any damage or corrosion that may have caused it to become stuck in the first place. If any is found, replace it with a new one before reattaching to your Stihl trimmer head. With these methods, you can easily remove a stuck bump knob and get your trimmer head back up and running!

How Do You Remove A Stuck Bump Knob?

Why Does My Trimmer Line Keep Coming Out?

If your trimmer head won’t come off and the trimmer line keeps coming out, it is likely because the housing that holds the trimmer line has become worn or clogged. Over time, dirt and debris can build up in the spool housing and cause it to get stuck. In addition, a damaged or worn-out trimmer head can cause problems as well. Fortunately, there are some easy fixes for this issue.

The first step is to clean out any dirt and debris from the spool housing. You can do this using a soft brush or compressed air to dislodge anything that may be stuck in there. Once you have cleared away all of the debris, check to make sure that the spool isn’t damaged or worn. If it is, you can purchase a new spool from a local hardware store and replace it yourself.

If the trimmer head still won’t come off, the next step is to inspect the nut that holds the trimmer head in place. Make sure that it is not rusted or stuck due to debris buildup. If there are any signs of rust or corrosion, use a wire brush or steel wool to clean it up before attempting to loosen the nut. You may need to use some force when loosening this nut so make sure you have something sturdy to hold onto while doing so.

Once the nut has been removed, check for any damage on the threads of the trimmer head shaft. If there is damage, you may need to purchase a new trimmer head and replace. If there isn’t any, then you should be able to unscrew the head from the shaft.

If these solutions have worked, you may need to take a trimmer in for repairs or replacement parts at a repair shop.

A professional will be able to identify the exact cause of your problem and provide you with the right solution. With some luck and patience, you can get your Stihl Trimmer Head off in no time! [5]


How do you remove the trimmer head off of a Stihl Weedeater?

The Stihl brand of weed eaters uses two different types of heads: the AutoCut and the PolyCut. To remove either one, first turn off the power to the trimmer and ensure that it is unplugged. Then locate the head retaining bolt on your trimmer. For AutoCut models, it can be found directly in front of the spinning head. For PolyCut models, you will need to block off one side of the line with a piece of cardboard before unscrewing it. Once you have located the bolt, use a wrench or socket to loosen it until you can pull it out by hand. Once removed, replace with a new trimmer head as necessary.

What should I do if my Stihl trimmer head won’t come off?

If your Stihl trimmer head won’t come off, there may be a build up of dirt or debris that is preventing the bolt from being loosened. Before attempting to take it apart further, use compressed air to clean around the area and remove any built up material. Additionally, you may need to use a lubricant like WD-40 to help loosen and break the seal between the head and bolt. If necessary, you can also replace the retaining bolt completely if it has become stripped or otherwise damaged.

What should I do if my Stihl trimmer line won’t feed?

If your Stihl trimmer line isn’t feeding properly then the first step is to check for any blockages. Make sure to clean out the area around your cutting head and the spool as needed. Then try resetting your trimmer by pressing down on the primer bulb located on the back of the machine a few times. If neither of these steps resolve your issue, you may need to replace your cutting head or line altogether in order to get it working properly again.

What other common issues can I encounter with my Stihl Weedeater?

Common issues that may arise with Stihl weed eaters include: an engine not starting, fuel leakage, spark plug problems, poor power output, or excessive vibration. If any of these occur, double check all connections and make sure that your machine is properly maintained and free of debris. If necessary, you may need to replace parts or components in order to get it back up and running again.

Are there any safety tips I should know before using my Stihl Weedeater?

Yes! Before starting your Stihl weedeater always make sure that the area around you is clear and free of any obstacles. Additionally, wear protective gear such as gloves, goggles, hearing protection, and a respirator when operating the machine. Make sure to read all instructions in the user manual before use and never leave the trimmer unattended while it is still running. Following these safety tips will help keep you safe from potential harm while using your Stihl weed eater.

How do you loosen a strimmer head?

If you’re struggling to remove the trimmer head from your Stihl trimmer, there are a few things you can try to loosen it. Before attempting to loosen the head, make sure that the trimmer is shut off and unplugged. First, check if there’s any debris or grass stuck in the space between the shaft and trimmer head. If present, use an old toothbrush or other small brush to dislodge it. This may be enough to loosen it so that you can unscrew the strimmer head by hand. If not, start by tapping around the edge of the strimmer head with a rubber mallet or similar tool, making sure not to hit too hard as this could damage the head. If tapping does not work, you may need to use a strap wrench or pliers to get sufficient grip and twist it off. Be sure to use caution when using these tools near the trimmer shaft. Lastly, if all else fails, you can try using an impact driver with a bit that matches the size of the strimmer head screws. After loosening and removing the trimmer head, be sure to clean out any remaining debris and grass before replacing or reattaching a new one.

Useful Video: How to replace your STIHL trimmer head AND how to fix it if it is STUCK!


Stihl trimmer head won’t come off problems can be annoying, but with a little bit of knowledge and the right tools, they don’t have to be. Before attempting to remove a stuck trimmer head, it’s important to ensure that you are using the correct size wrench or socket and enough force. If more force is needed, use a hammer or an air tool as appropriate. If all else fails, take your Stihl trimmer into an authorized service center for proper diagnosis and repair. With some patience and know-how, your Stihl trimmer will soon be running like new again!