How To Install a Universal Trimmer Head

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Whether you are a landscaping professional or an enthusiastic DIYer, one of the best ways to keep your landscape looking great is to keep your trimmer in good working order. That means replacing the string when needed and keeping it sharpened and ready to go hence this guide on how to install a universal trimmer head.

However, it also means that you can do so quickly and easily if you need to replace the trimmer head itself. And when replacing a trimmer head, you have only two options: either a fixed or universal trimmer head. In this case, we major more on universal trimmer head installation.

While universal trimmer heads are designed to work on various trimmers, some of them may not be compatible with all trimmers. So if you have a particular trimmer in mind, then look for a universal head that is compatible with it. If you are replacing an old head, then look for one compatible with the same trimmer.

Eager to learn more about universal trimmers? Keep reading to learn more.

Factors To Consider When Installing Universal Trimmer Head

How To Install a Universal Trimmer Head
Universal Trimmer Head

Switching out your trimmer’s cutting head for a Universal Trimmer Head can take your lawn care to the next level. You’ll be trimming your lawn in no time! Before getting started, there are a few factors you should consider.

The Shape and Size of Your Trimmer Head

The shape and size of your trimmer head are significant factors to consider when looking for a replacement. Traditionally, the shape of the trimmer head would indicate the type of line to use on the spool.

However, today, you can use most trimmer heads with multiple lines depending on preference. In a nutshell, most trimmer heads come in either round or square shapes. The round trimmer head is typically used with monofilament or twisted lines, while square trimmer heads work great with serrated lines.

Ultimately, the size of the trimmer head will also affect your installation. The trimmer head should fit comfortably on your tool.

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Selecting a Universal Weed Eater Head

Depending on your needs, you should consider a few factors when choosing the best universal trimmer head. Consider what types of vegetation you need to cut through and the width of those areas.

Also, think about the durability and strength of your weed eater itself to find a compatible trimmer head that does not overwork it. If possible, test out different blades before making a buying decision.


The price of a trimmer head can vary depending on its features and brand. You should buy one that fits within your budget. However, you should not go for one with cheap quality just because it is cheap. You will end up replacing them in a few days.

Compatibility With Your Trimmer

There are many different universal trimmer heads, some of which may not be compatible with your trimmer. However, here’s how to determine the compatibility of the Universal Trimmer Head with your current tool.

  • Check your shaft size.

The Universal Trimmer Head comes in 1″ and 1-1/8″. Measure the diameter of your shaft to know which one to buy.

  • Check if your shaft is curved or straight.

If it’s curved, you need a curved-shaft Universal Trimmer Head and vice versa for straight-shaft ones.

  • Check if your shaft is solid or split.

Solid-shaft Universal Trimmer Heads are only compatible with solid-shaft trimmers, while split-shaft models can be attached to either a solid- or split-shaft trimmer.

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Your trimmer head should be durable enough to withstand harsh weather conditions like rain or snow without getting ruined easily. This means that they should withstand rough handling and regular use during trimming sessions without any damage occurring to them.

By considering the above factors, you will determine if the head you are aspiring to buy is compatible with your initial trimmer.

How To Install a Universal Trimmer Head

Installing the Universal Trimmer Head is a simple task that should take only a few minutes to complete. However, the key to a successful installation is ensuring you use the correct shaft size and that the tip will fit comfortably to your trimmer line. Here is how to install your universal trimmer head.

1. Unpack the Trimmer Head

Before installing your universal trimmer head, you must first remove it from the packaging and check that all its parts are present.

If any parts are missing, contact the company’s customer service team immediately so that they can send you a replacement free of charge.

2. Remove the Old Trimmer Head

Remove the bolt that holds the old trimmer head to the shaft. As a locking nut, this bolt is designed to be difficult to loosen. To loosen it, use a screwdriver or other tool with a flat edge to hold the head in place while turning the lock nut with your wrench.

Once you’ve loosened it enough, continue turning by hand until you can remove it altogether.

Remove the old trimmer head from the shaft of your trimmer. It may pull off easily at this point; however, if your line has been cut off too short (shorter than 1″), it may catch on something inside your machine and need some coaxing out with a tool such as pliers or wire cutters.

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3. Install the Universal Trimmer Head on the Shaft of Your Machine

After you have removed the old head, place the universal trimmer on the shaft of your machine. Use the instructions that came with the head to find the correct position of the shaft. Foremost, you will need to use a screwdriver to loosen the trimmer head’s knob.

After loosening your trimmer head’s knob:

  1. Pull both ends of your string out of one side until they are taut and parallel.
  2. Find an empty hole on one side and push a fortune into it until it is through to come out another open hole.
  3. Repeat this step with both ends and tie the two ends together again, just as before.

Then, tie a knot at one end of each string, leaving enough room between them to easily pull apart when installing or replacing the strings later on.

4. Follow Instructions for Tightening and Adjusting the Knob and String

Next, tighten the knob that holds the head-on. Turning it clockwise will tighten the head more firmly, while counterclockwise will loosen it. So tighten the knob by turning it clockwise until it is firm and secure enough to withstand any force when trimming.

Additionally, the string should extend to about 1/4 inch long, but not to the extent that your trimmer may get stuck or tangled in grasses or weeds. In essence, once you’ve tightened the knob just right, try spinning the string around a few times to see if it’s an even length.

If some parts are longer than others, take them off and adjust until each part is equal. However, don’t over-tighten your universal trimmer head, as it can damage the whole tool.

No matter what kind of trimmer head you’re working with—brush cutter, line trimmer, mower, brush hog or other—the installation process is the same. The benefit of using a universal trimmer head like the Husqvarna 537388101 Universal is much easier to use.

It’s compatible with almost any line trimmer on the market; all you need to do is adjust it to fit your needs. And if you already have a traditional trimmer head installed, there are manual tools that you can use to change its mounting position.

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