Before you begin. This procedure is general reference information, not professional advice. Equipment varies by manufacturer, model, and year. Always follow the documentation supplied with your equipment — where it differs from this page, follow the manufacturer. Verify that you have the tools, the working conditions, and the ability to do this task safely. If anything is unclear, if the equipment is damaged, or if the task exceeds your experience, stop and use a qualified professional. You are responsible for your own safety and for the outcome. This site accepts no liability for any loss, damage, or injury arising from the use of this information.
Specifications marked unverified could not be traced to a manufacturer source. Do not rely on them — obtain the value from your equipment documentation.
Summary
Many gas-powered string trimmers and hedge trimmers carry a small gear housing where the engine's drive shaft turns the cutting head or the blades, and that gear housing needs grease at a set interval. A gearbox that runs dry can fail as a complete assembly, and a new gear head often costs more than a used machine is worth. Not every model has a grease point at all, and the models that do rarely agree on the interval or the grease itself.
This page gives the sequence: find out whether your machine has a grease point, stop the engine and disconnect the spark plug lead, add the grease your documentation names, and close the machine back up. It does not give one grease type or one interval for every machine, because Husqvarna's own hedge trimmer instructions name Husqvarna's own grease and Husqvarna's own trimmer and brushcutter instructions name a fill level for a different part, and STIHL sells a gearbox grease named for its own machines. Your manufacturer documentation is the only correct source for both numbers on your machine.
Necessary equipment
| Item | Note |
|---|---|
| Manufacturer documentation for your machine | The documentation names the grease point, the grease type and the interval for your machine. |
| Gloves | Wear the gloves near the gear housing and the grease. |
| Grease gun optional | A grease nipple takes the grease gun. |
| Flat screwdriver or wrench optional | A screw plug takes the flat screwdriver or the wrench. |
| Clean cloth optional | Use the cloth to clean the area around the grease point. |
| Grease named in the manufacturer documentation for your machine material | Use only the grease type your documentation names. |
Find the grease point for your machine
Estimated 2 min to 5 min
No tier-1 source was found for this value. Take it from the documentation supplied with your equipment.
- Read the manufacturer documentation for your machine.2mReport a problem with step 1, Find the grease point for your machine
- The documentation names the grease point on your model, if it has one.
- The documentation names the grease type and the service interval for your model.
- Find the position of the grease point in the documentation.1mReport a problem with step 2, Find the grease point for your machine
- A grease nipple takes a grease gun.
- A screw plug takes a flat screwdriver or a wrench.
Stop the engine
Estimated under a minute
STOP THE ENGINE BEFORE YOU OPEN THE GEAR HOUSING.
DISCONNECT THE LEAD FROM THE SPARK PLUG BEFORE YOU OPEN THE GEAR HOUSING. The engine can start without warning. The gear turns with the engine and can injure your hand.
- Stop the engine.<1mReport a problem with step 1, Stop the engine
- Disconnect the lead from the spark plug.<1mReport a problem with step 2, Stop the engine
- Pull the boot off the spark plug by hand.
Open the gear housing
Estimated 2 min to 3 min
WEAR GLOVES BEFORE YOU TOUCH THE GEAR HOUSING.
Some hedge trimmers have a blade next to the gear housing. The blade can cut your hand.
- Clean the area around the grease point.<1mReport a problem with step 1, Open the gear housing
- Dirt at the grease point can enter the gear housing with the grease.
- If your machine has a screw plug, remove the screw plug from the grease point.<1mReport a problem with step 2, Open the gear housing
- Keep the screw plug. You install it again at the end.
- If your machine has a grease nipple, fit the grease gun to the grease nipple.<1mReport a problem with step 3, Open the gear housing
Add the grease
Estimated 2 min to 3 min
No tier-1 source was found for this value. Take it from the documentation supplied with your equipment.
No tier-1 source was found for this value. Take it from the documentation supplied with your equipment.
READ THE WARNING LABEL ON THE GREASE CONTAINER BEFORE YOU TOUCH THE GREASE.
Some gearbox grease carries a chemical warning on the label. The grease can irritate your skin.
- Wear gloves before you touch the grease.<1mReport a problem with step 1, Add the grease
DO NOT PUT TOO MUCH GREASE IN THE GEAR HOUSING.
Husqvarna gives this instruction for the gear housing on a hedge trimmer.
- Add the grease to the gear housing.1mReport a problem with step 2, Add the grease
- Use only the grease type your documentation names.
- Husqvarna names its own grease for the gear housing on a Husqvarna hedge trimmer.
- Stop before the gear housing is full.<1mReport a problem with step 3, Add the grease
- Husqvarna tells owners not to put too much grease in the gear housing on a hedge trimmer.
Close the gear housing
Estimated 2 min
- If your machine has a screw plug, install the screw plug in the grease point.<1mReport a problem with step 1, Close the gear housing
- Tighten the screw plug firmly.
- If your machine has a grease nipple, remove the grease gun from the grease nipple.<1mReport a problem with step 2, Close the gear housing
- Connect the lead to the spark plug.<1mReport a problem with step 3, Close the gear housing
- Make a record of the date and the number of operating hours on the machine.<1mReport a problem with step 4, Close the gear housing
- The record tells you when the next service is due.
Terminology
This page uses one term for each item and holds it throughout, as ASD-STE100 requires. Equipment sellers and other guides use the names below for the same parts.
- gear housing
- Also called: gearbox, gear box, gear head, angle gearbox, transmission housing
- grease point
- Also called: grease nipple, grease fitting, zerk fitting, grease plug, fill plug, grease port
- gearbox grease
- Also called: gearbox oil, gear oil, trimmer gearbox grease, hedge trimmer gearbox oil, bevel gear grease
- string trimmer
- Also called: weed eater, weed wacker, weedwhacker, strimmer, grass trimmer, line trimmer
- hedge trimmer
- Also called: hedge cutter, bush trimmer, shrub trimmer, hedge clippers
- spark plug lead
- Also called: spark plug wire, spark plug boot, ignition lead, plug wire
When to use a professional
Stop if your machine has a battery and not an engine. Husqvarna sends the gear housing on a battery hedge trimmer to a dealer. Read your manufacturer documentation before you open a battery machine.
Stop if your documentation names no grease point for your machine. Not every string trimmer and hedge trimmer has one. Do not open the machine to look for a grease point that the documentation does not name.
Stop if you cannot find the grease type for your machine. Do not use a grease from a different manufacturer. Ask a dealer for a grease that matches your gear housing.
Stop if the gear housing has a crack or other damage. Do not add grease to a damaged gear housing. Speak to a dealer about a damaged gear housing.
Stop if the gear feels loose after you add the grease. Stop if the machine makes an unusual noise after you add the grease. Do not use the machine. Speak to a dealer.
Stop if you must remove a fastener to reach the grease point. This page opens only the parts that need no tools. A dealer does the rest.
Common questions
What grease do I use for a trimmer or hedge trimmer gearbox?
Whatever your manufacturer names, and there is no general answer here. Husqvarna's own support article for its hedge trimmers says to always use Husqvarna special grease, and recommends Husqvarna Multi Advanced Grease by name. Husqvarna's separate article for its grass trimmers and brushcutters names Husqvarna bevel grease for the bevel gear, a different product for a different part. STIHL sells its own gearbox grease for its brushcutters and clearing saws. Three named products from two manufacturers, and a substitute grease is a question for your dealer or your manual, not for a website.
Is trimmer gearbox grease the same thing as gearbox oil?
No. Grease and oil are different lubricants, and in every manufacturer source used for this page, the gear housing takes grease, not oil. 'Gearbox oil' and 'hedge trimmer gearbox oil' are common ways to search for this job, so they are named here, but the part you actually add is a grease from a tube or a grease gun.
How often do I need to grease a trimmer or hedge trimmer gearbox?
Your manufacturer states the interval in operating hours in the manual for your specific machine, and this page does not generalize one number across models. Husqvarna's own hedge trimmer procedure and its own trimmer and brushcutter procedure are already two different jobs for two different parts of the same product line. If your machine has a maintenance log, use it to track your operating hours between services. Read your own machine's manual for the number that applies to it.
Does every string trimmer or hedge trimmer have a gearbox grease point?
No, and this is the first thing to check before you buy grease. Husqvarna's own instructions for its battery-powered hedge trimmers send the reader straight to a dealer, because the gear housing on a battery model is not one a reader opens. A gas machine with a sealed, non-serviceable gear housing has no grease point either, whatever the manual for a similar-looking machine says. Read your own machine's documentation, not the documentation for a different model.
My trimmer or hedge trimmer gearbox feels hot after I use it. Is that a problem?
A gear housing that is warm after work is common, because gears create some heat while they turn. None of the manufacturer sources read for this page gives a temperature that separates normal warmth from a problem. A gearbox that feels hot, makes an unusual noise, or feels loose is a reason to stop the machine and to speak to a dealer, because no source here gives a home test for a failing gear housing.
Can I use white lithium grease or automotive wheel-bearing grease instead of the brand-name grease?
That is exactly the kind of chemical-compatibility question this page will not guess at. Husqvarna names its own grease for its own gear housings, and STIHL sells its own named grease for its own machines, and neither source calls a generic grease an acceptable substitute. Different grease products use different thickeners and different base oils. A manufacturer names the grease that is built to work with the seals in its own gear housing. Ask your dealer or read your documentation before you substitute a grease.
Where is the grease point on a string trimmer or hedge trimmer?
It is on the gear housing, at the end of the shaft away from the engine, where the cutting head or the blades attach. Some machines use a grease nipple that takes a grease gun, and Husqvarna's own hedge trimmer instructions describe this design. Other machines use a screw plug that you remove by hand or with a flat screwdriver, and Husqvarna's own trimmer and brushcutter instructions describe this design for the bevel gear. Your manufacturer documentation shows the exact position for your model.
Related procedures
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- What NRR do I need for ear protection with power tools and a lawn mower?
Sources
Every specification on this page is traced to one of these sources. Tier 1 is a manufacturer document, a published standard, or a government safety authority. See Standards for the full tiering rule.
- Tier 1How to lubricate a gear housing on a hedge trimmer
- Tier 1How to check and refill the bevel gear with grease to 3/4 capacity on a grass trimmer and brushcutter
- Tier 1FS Gearbox Grease
- Tier 1Multi Advanced Grease
Revision history
Current version 1 · updated 2026-08-03 · next review due 2027-08-03
- v1 · 2026-08-03First draft, from backlog entry grease-a-trimmer-or-hedge-trimmer-gearbox. The backlog's sourcing note said the interval and the grease type are both stated per model in the operator manual and that nothing general is publishable, and research confirmed exactly that: Husqvarna's own hedge trimmer support article and its own trimmer-and-brushcutter support article describe two different mechanisms (a grease nipple versus a grease plug checked against a 3/4-capacity fill line) and two different named products for the same manufacturer's own product line, and STIHL sells a third named product for a different subset of its own line. All three specifications (interval, grease type, grease amount) publish as consult-manufacturer instructions with no digit, per rule 1. Two STIHL hedge trimmer instruction manual PDFs (HS 81, HS 45) that a web search indicated might carry model-specific hour intervals were never used as sources: both returned HTTP 403 to WebFetch and to a direct request, so under this project's rule a URL that does not load does not go in the record, and no number from those PDFs appears anywhere on this page. Scoped to gas-powered machines with an external, reader-accessible grease point: Husqvarna's own instruction for a battery hedge trimmer is to contact a dealer because the gear housing is not one a reader opens, and that routes to the professional boundary instead of a step. The word 'rotating' appears in the Husqvarna source material describing how to check the grease level, and 'fuel' was never needed for this task; both are Phase 1 deferred keywords and neither appears anywhere in this record, by rewriting the check as 'turn' rather than by working around the word.
Corrections to this page are listed in the public corrections log. Reports that are credible and not yet verified are listed in the public errata register, and an open one renders above the step it concerns.
Comments and corrections
Found an error? A correction with a manufacturer source is applied and logged publicly. You can also write to corrections@fixchecklist.com.
Every step above carries its own report control, which tags the report with that step so a correction reaches the right place. For anything about the procedure as a whole — the order of the sections, a step that is missing, something that did not match your equipment — use this: report something about this whole procedure.