Introduction
Dewalt weed eaters are a top choice for both DIY homeowners and professional landscapers, known for their durability, power, and reliable performance. But even the best trimmer will struggle if its cutting string is worn, frayed, or broken. If you’ve been searching for a clear guide on how to change weed eater string on Dewalt tools, this comprehensive resource will walk you through every step of the process, share pro tips to extend string life, highlight common pitfalls to avoid, and answer frequently asked questions to help you complete the task quickly and correctly. No prior experience is needed – this guide is designed for users of all skill levels.
Understanding Your Dewalt Weed Eater
Before diving into the replacement process, it’s helpful to understand the basics of your Dewalt trimmer, as different models may have slight variations in their string head design. Dewalt offers a range of corded and cordless string trimmers, including the 20V MAX, 40V MAX, and corded commercial-grade lines, all designed for heavy-duty residential and professional use. The most popular models include the 20V MAX DCST920P1, a compact cordless option ideal for small to medium yards, the 40V MAX DCST942P1, a high-power model for thick weeds and overgrown areas, and the corded DCMHT773, a reliable choice for users who prefer consistent power without battery limitations.
Most consumer-grade Dewalt weed eaters use a bump-feed string head, which advances the string automatically when you tap the head against the ground while the trimmer is running. Some commercial models use a fixed-line head, which requires manual adjustment of the string length. Dewalt trimmers are designed to work with round or square cross-section trimmer string, typically in 0.080-inch or 0.095-inch diameters, depending on your model’s specifications. Round string is best for light grass and weeds, while square string provides a cleaner cut for thicker, woody vegetation. Always check your user manual for the correct string type and diameter for your specific model, as using incompatible string can cause poor performance or damage to the trimmer.
When to Change Your Weed Eater String
Knowing when to replace your string will save you from frustrating jams, uneven cuts, and unnecessary strain on your Dewalt trimmer’s motor. Replace your string immediately if you notice fraying, splitting, or visible notches from hitting hard surfaces, if the string breaks frequently during use, if the trimmer leaves uneven patches of grass, or if the string is shorter than 2-3 inches. For regular users, replacing the string every 2-3 months or after 10-15 hours of use will keep your trimmer performing at its best. If you ignore worn string, you risk damaging the head mechanism, burning out the motor, and leaving your yard looking unkempt.
Safety Precautions Before You Start
Safety should always be your top priority when working with power tools. Before beginning the replacement process, always disconnect the power source – remove the battery from cordless models or unplug corded trimmers – to prevent accidental startup. Wear work gloves to protect your hands from sharp string edges and small metal parts, and consider wearing safety glasses to guard against flying debris or loose string ends. Work in a well-lit, flat area to avoid losing small components like retention rings or string ends, and keep children and pets away from your work area while you complete the replacement.
Tools and Materials You’ll Need
The good news is that changing your Dewalt weed eater string requires no special tools, making it a quick and easy DIY task. You will need the following items: a replacement trimmer string (either Dewalt OEM pre-wound spool or universal string cut to the correct length for your model), a pair of sharp scissors or wire cutters to cut the string to size, a clean rag to wipe away any grass or debris from the string head, and your Dewalt trimmer’s user manual (optional, but helpful for model-specific details). If you are using universal string instead of a pre-wound spool, you will also need a small flathead screwdriver to help wind the string evenly around the spool. If cutting your own string, measure the length carefully against your manual’s specification – most Dewalt models require 10 to 15 feet of string for a full spool.
Step-by-Step Guide: How to Change Weed Eater String on Dewalt
Now that you’re prepared, follow these simple steps to change your Dewalt weed eater string correctly, whether you’re using a pre-wound spool or cutting your own string from a bulk roll. This process works for nearly all Dewalt bump-feed and fixed-line string trimmer models.
- Prepare your trimmer: Place your Dewalt weed eater on a flat, stable surface with the string head facing upward. For cordless models, remove the battery pack by pressing the release button on the battery and sliding it off the trimmer’s base. For corded models, unplug the power cord from the outlet. This step is critical to prevent accidental startup while you work. Wipe away any built-up grass, dirt, or debris from the exterior of the string head with a clean rag to keep dirt from entering the mechanism during replacement. If your trimmer has an adjustable handle or shoulder strap, you may want to adjust it to a comfortable height before laying it down to make the head easier to access.
- Remove the old string and spool: Locate the retention ring or cap that holds the spool in place. On most Dewalt models, this is a plastic ring that twists counterclockwise to release, or a small clip that you pry open with a flathead screwdriver. Once the retention ring is removed, pull the old spool straight out of the head. Pull out any remaining old string by hand, or use your screwdriver to gently pry loose stuck pieces. If the spool is stuck, gently wiggle it back and forth while pulling to loosen it, and spray a small amount of penetrating oil around a stuck retention ring if needed.
- Prepare the new string: If you are using a pre-wound Dewalt OEM spool, skip to the next step. If you are cutting your own string, cut a length that matches the specification in your user manual – most Dewalt models require 10 to 15 feet of string. Take one end of the string and feed it through the small anchor hole on the center of the spool, leaving 6 to 8 inches of string sticking out of the hole. Wind the string evenly around the spool in the direction indicated by the arrow printed on the spool (almost always clockwise for Dewalt models) – avoid overlapping the string as you wind, as this can cause jams when feeding. Once the spool is full, tuck the loose end of the string into the notch on the edge of the spool to secure it in place.
- Reassemble the string head: Align the spool with the exit holes in the trimmer head, making sure the loose ends of the string are sticking out of both holes (for bump-feed models) or the single exit hole (for fixed-line models). Insert the spool into the head until it clicks into place. Replace the retention ring or cap, twisting it clockwise or snapping the clip closed to secure the spool. Pull the loose string ends gently to confirm they feed smoothly through the exit holes.
- Test the trimmer: Reconnect the battery or plug in the trimmer, then hold it upright and activate it. For bump-feed models, tap the head lightly against a hard, flat surface two to three times to advance the string, then test the trimmer on a small patch of grass. If the string cuts evenly and advances properly, you’ve successfully completed the replacement. If the string does not advance, double-check that you wound the string in the correct direction and that it is not tangled inside the head.
Pro Tips for Longer String Life
With a few simple habits, you can extend the life of your Dewalt weed eater string and reduce how often you need to replace it. First, always use the correct string diameter for your model – 0.080-inch for most consumer models, 0.095-inch for heavy-duty commercial units – as using too thick a string overloads the motor and causes frequent breakage. Second, avoid trimming near rocks, pavement, or tree trunks, as these hard surfaces fray and notch string quickly. Third, wind the string evenly without overlapping to prevent jams and uneven wear. Fourth, store your trimmer and extra string in a cool, dry place, as moisture and extreme heat make string brittle and prone to breaking. Finally, keep a spare pre-wound spool on hand for quick replacements when you’re out working, so you never have to stop a job mid-way.
Common Mistakes to Avoid
Even experienced users can make simple errors when changing their weed eater string, leading to poor performance or damage to the trimmer. Avoid these common mistakes: first, never overfill the spool – leave a small gap between the wound string and the edge of the spool to allow for smooth feeding. Second, winding the string in the wrong direction – if you wind it counterclockwise on a model designed for clockwise winding, the string will not advance when you bump the head, and may even tangle inside the mechanism. Third, using string that is too thick for your model – check your user manual for the recommended diameter, as using 0.095-inch string on a model designed for 0.080-inch can burn out the motor. Fourth, forgetting to disconnect the power source before starting work, which can lead to accidental startup and serious injury. Fifth, not securing the loose end of the string in the spool notch before reassembling, leading to unraveling and jams. Finally, misaligning the spool when inserting it into the head – make sure it is seated fully and the retention ring is tightened securely to ensure proper string feed.
Comparison of Dewalt vs. Aftermarket Trimmer String
One of the most common questions Dewalt owners have is whether to use OEM Dewalt replacement string or third-party universal string. Both options work well for most users, but there are key differences to consider. The table below breaks down the pros and cons of each option to help you make the best choice for your needs.
| Feature | Dewalt OEM Replacement String | Third-Party Universal String |
|---|---|---|
| Compatibility with Dewalt Heads | Perfect fit, no adjustments needed | Compatible with most models, but may require minor trimming for older heads |
| Average Lifespan | 12-18 months with regular use | 6-12 months with regular use |
| Cutting Efficiency | Consistent, clean cuts for all grass and weed types | Variable performance; high-quality brands match OEM, low-quality brands fray quickly |
| Resistance to Wear | High resistance to notches and fraying from hard surfaces | Varies by brand; premium options are comparable, budget options wear quickly |
| Price Point | $8-$12 per pre-wound spool | $4-$8 per bulk roll or pre-wound spool |
| Warranty Coverage | Covered under Dewalt’s 3-year limited warranty when used with official Dewalt parts | No Dewalt warranty coverage; covered by third-party manufacturer warranty if applicable |
Troubleshooting Common Issues
Even after following the replacement steps correctly, you may encounter a few common issues with your Dewalt weed eater string. Here’s how to fix them: if the string does not advance when you bump the head, first check that you wound the string in the correct direction (the arrow on the spool indicates the right direction). If the direction is correct, check for tangles inside the head – remove the spool and untangle any twisted string. If the string breaks frequently during use, you may be using string that is too thick for your model, or you may be trimming near hard surfaces too often. Replace the string with the correct diameter and avoid rocks and pavement when possible. If the trimmer leaves uneven cuts, check that the string is sharp and not frayed – replace it if it has visible notches, and make sure the spool is not overfilled, as this can prevent the string from extending fully. If the motor runs but the string does not spin, check that the spool is installed correctly and the retention ring is tight – a loose spool will not rotate with the head.
Frequently Asked Questions
How often should I change my Dewalt weed eater string?
For most users, replacing your Dewalt weed eater string every 2 to 3 months, or after 10 to 15 hours of regular use, will keep your trimmer performing optimally. If you frequently trim near hard surfaces like rocks or pavement, you may need to replace the string more often, as these surfaces cause rapid fraying and notching. If you use your trimmer for heavy-duty jobs like clearing thick brush, you may need to replace the string as often as once a month.
What size string does my Dewalt weed eater use?
Most Dewalt 20V MAX and 40V MAX string trimmers use 0.080-inch diameter round or square string, while heavy-duty commercial models may use 0.095-inch string. Always check your user manual for the exact specification for your model, as using the wrong diameter can damage the motor or cause poor performance.
Can I use aftermarket string in my Dewalt weed eater?
Yes, most Dewalt weed eaters are compatible with high-quality third-party universal trimmer string. Just be sure to use the correct diameter for your model, and avoid low-quality budget string, which frays quickly and can cause jams. Dewalt OEM string is designed for perfect compatibility and maximum durability, but aftermarket options are a cost-effective choice for casual users.
Why is my new Dewalt weed eater string jamming?
String jams are almost always caused by one of three issues: the string was wound in the wrong direction, the spool was overfilled with string, or the loose end of the string was not secured properly in the spool notch before reassembly. To fix the jam, remove the spool, untangle any twisted string, rewind the string in the correct direction, leave a small gap between the string and the spool edge, and tuck the loose end into the notch before putting the spool back in place.
How do I know if my Dewalt weed eater string is worn out?
You should replace your string if you notice visible fraying, splitting, or notches along the length of the string, if the string breaks frequently during use, if the trimmer leaves uneven patches of grass after cutting, or if the string is shorter than 2 to 3 inches. Even if the string looks intact, replacing it every few months will prevent unexpected breakage during use.
Can I sharpen a dull weed eater string instead of replacing it?
No, you should never attempt to sharpen trimmer string. The string is designed to be flexible and lightweight, and sharpening it will make it brittle and prone to breaking. It is also much faster and cheaper to simply replace the string with a new piece, as replacement string is inexpensive and widely available.
Conclusion
Changing your Dewalt weed eater string is a simple, 10-minute task that will keep your trimmer running smoothly and extend its lifespan. By following the step-by-step guide outlined above, using the correct string for your model, and avoiding common mistakes, you can master the process quickly and get back to maintaining your yard with ease. Remember to prioritize safety by disconnecting power before starting work, wind the string evenly in the correct direction, and use high-quality string to reduce how often you need to replace it. Whether you choose Dewalt OEM string or a reliable aftermarket option, proper maintenance of your trimmer’s string will ensure consistent, clean cuts for every use. Regular maintenance of your Dewalt weed eater, including timely string replacement, will keep your tool running like new for years, saving you money on replacements and ensuring your yard always looks its best. Now that you know exactly how to change weed eater string on Dewalt tools, you can tackle overgrown grass and weeds with confidence all season long.