So we don’t get confused here, we’re talking about the entire head falling off the weed eater. Not just the head cap and spool falling off. You know, when the whole head falls off, and you’re just left with the shaft and guard at the end of your weed eater. Sound familiar? Well, if this describes your weed eater issue, then let me explain what’s going on.
Why Your Weed Eater’s Head Keeps Falling Off (The Short Answer)
A common feature of weed eaters is they use a bearing housing to transfer the motion of the flex cable to the weed eater spool head. A bolt holds the bearing housing to the shaft, and a tiny c-washer holds the bearing shaft in the housing. If either of these items fails, your weed eater’s head will fall off.
2 Possible Reasons Your String Trimmer Head Keeps Falling Off
If you have a weed wacker, like a Stihl FS38, 40, 45, or even an FS46, then you could already be familiar with the head coming off. It’s kind of a common problem these types of curved shaft string trimmers have as they use a simple bearing housing. So, let’s take a closer look.
Checking the C-Washer Clips
If you look at the weed eater head and find that you have a metal bar pointing out of one end, this is the bearing housing shaft. If you inspect the bar, you’ll find a tiny groove at the end. This is where the c-washer clip should be located. So, if this is the case, you now know why your weed eater head keeps falling off. A missing c-washer clip.
Checking the Bearing Housing Bolt
Now, if you look at the end of the weed eater head and find more than just the metal bar, then you have a different issue. So, in this scenario, the c-washer clip is still in place, and you have a metal tube and a couple of washers on the bar. This means the entire bearing housing has come out.
If you take a look at the side of the metal tube, also known as the bearing housing, you find a threaded hole. This is where the housing bolt secures the bearing housing in place. Now, if the threads look damaged, then you might need to replace the entire bearing housing, but if it looks good, then you could just need a new bolt.
How to Fix a Weed Wacker Head That Keeps Coming Off
So, if your weed eater’s head keeps falling off, then hopefully, one of these fixes will help you out. Let’s dive in.
Replace the C-Washer Bearing Housing
To start this fix, you’ll need to remove the line head. Use a socket wrench to remove the nut from the underside of the head and remove the bar. Next, grab a screwdriver and remove the screw holding the guard on the shaft of the weed eater. Then, remove the housing bolt from the shaft.
Take a pair of channel locks and pull the bearing housing from the weed eater’s shaft. Be careful when pulling the bearing from the shaft as the c-washer clips will probably still be on the bearing.
Now it’s decision time. Inspect the groove in the bar and see if it has worn down. If it has, then the c-washer clip will probably just fall off again if you reinstall it. So, it could be time for a replacement bearing housing. But if you want to give it a try, then make sure you have the parts in the correct order. Bar, washer, housing, washer, then the c-washer clips.
Attach the parts in order, then use a pair of pliers to press the c-washer back into the groove on the bar. Finally, reinstall the head housing, including the housing bolt, and reattach the guard and the head.
Tools Required to Install C-Washer Clip on a Weed Eater
- Socket Wrench
- Channel Locks
Replacing the Housing Bolt
If you have read over how to replace the c-washer clip, then you know where the housing bolt should go. But just to make sure, here are the steps.
Steps to Replace a Housing Bolt
- Remove the nut from the underside of the weed eater head.
- Remove the head from the weed eater.
- Remove the screw holding the guard in place.
- Slide the guard out of the way.
- Take the original housing bolts or a replacement and fix them into place.
- Reposition the guard.
- Install the guard screw.
- Attach the head to the metal bar of the bearing.
- Install and tighten the head nut.
Toots Required to Install the Bearing Housing Bolt
- Socket Wrench
How to Prevent Your Trimmer’s Head Spinning Off Again
With this type of weed eater, there isn’t really anything you can do about the c-washer clip coming off. It’s just a normal wear and tear problem. But when it comes to the housing bolt, you can keep an eye on it and make sure you tighten it if you notice it coming loose.