A boot lid that drops without warning is more than annoying – it is a safety issue. If you are looking up how to replace gas struts, chances are your bonnet, boot, tailgate or canopy window is no longer staying open properly, or it feels weak and unreliable. The good news is that replacing worn struts is usually straightforward. The part that matters most is getting the right strut and fitting it safely.
How to replace gas struts safely
Gas struts are pressurised supports designed to hold weight and control movement. You will find them on boots, bonnets, tailgates, canopies and some interior compartments. Over time, seals wear out, pressure drops and the strut loses lifting force. Heat, heavy use and exposure to the weather can all speed that up, especially in Australian conditions.
Before you remove anything, support the panel securely. Never rely on one tired strut to hold up a heavy lid while you work on the other side. A solid prop, a second person or a suitable stand makes the job much safer. This is particularly important on larger SUVs, 4WD tailgates and heavy ute canopies, where the panel weight can catch people out.
Signs your gas struts need replacing
Most failing struts give you a bit of warning. The panel may drift down slowly, need a shove to stay up, or fail to rise on its own. You might also notice oil residue around the shaft or end seal, which can point to internal failure. If one side has weakened, it is best to replace both struts together so the load stays balanced.
A common mistake is assuming a strut only needs changing once it completely fails. In practice, weakened struts can place extra strain on hinges, brackets and mounting points long before that happens.
Choosing the right replacement strut
This is where many DIY jobs go off track. Gas struts are not one-size-fits-all. The correct replacement needs to match the extended length, compressed length, end fittings and force rating. If the force is too low, the panel will not stay up. Too high, and it may open too aggressively or put stress on the hinges.
In some cases, the original strut will have a part number and force measurement printed on the body. That is a good starting point, but it is still worth checking dimensions carefully. Vehicles can have variations between model years and body styles, and aftermarket accessories such as canopies or custom lids can change what is needed.
Orientation also matters. Many gas struts are designed to be installed with the shaft facing downward when closed. This helps keep the internal seal lubricated and can extend service life. If you fit them the wrong way around, they may still work, but often not as well or for as long.
Tools you may need
For most standard replacements, the tool list is short. You may need a flathead screwdriver or pick to lift retaining clips, gloves for grip, and a secure prop to hold the panel in place. Some setups use bolts rather than clip-on sockets, so a spanner or socket set may also be needed.
The actual job is often quick. The preparation is what keeps it safe.
Step-by-step: how to replace gas struts
Start by opening the bonnet, boot or tailgate fully and supporting it properly. If there are two struts, leave both attached until the panel is secure. Do not remove both at once unless the panel is independently held up.
Check how the old strut is mounted before removal. Take note of the end fitting style and which end faces up or down. A quick photo on your mobile can save guesswork later.
If the strut uses ball joints with retaining clips, gently lift the clip just enough to release the socket. There is usually no need to remove the clip completely. Once loosened, the socket should pop off the ball stud. Repeat at the other end and remove the strut.
Compare the old and new struts side by side. The length, fittings and body shape should be consistent. A small visual difference is not always a problem, but major variation is a sign to stop and double-check.
Fit the new strut by pressing the sockets onto the ball studs. If clips are used, make sure they seat securely. For bolted fittings, tighten them to the correct specification without overtightening. If you are replacing a pair, do one side at a time so the panel remains supported and aligned.
Once both are installed, carefully remove the prop and test the movement. The panel should open and close smoothly, stay in position and feel evenly supported. If it jerks, binds or sits unevenly, inspect the mounting points and check that the struts are correctly matched.
Should you replace one strut or both?
Technically, you can replace a single failed strut if the other is still in excellent condition. In reality, that is uncommon. Gas struts tend to wear at a similar rate, so replacing both at the same time is usually the smarter and more cost-effective option. It gives more even performance and reduces the chance of a second failure soon after the first.
This matters even more on heavy panels. A strong new strut paired with a weak old one can create uneven lift and extra stress through the hinges.
Common problems after fitting new gas struts
If the new struts do not perform as expected, the issue is usually one of three things: the wrong force rating, the wrong length or poor fitment. A strut that is too short may prevent full opening. One that is too long can overextend the lid or distort the hinge geometry.
Cold weather can make struts feel slightly firmer or slower, while high heat can affect their behaviour differently. That is normal to a point. What is not normal is a new strut that cannot hold the panel up safely or causes the panel to fly open too hard.
Mounting hardware can also be the hidden issue. Worn ball studs, bent brackets or cracked mounting points can stop even the correct strut from working properly. If the panel still sags or shifts after replacement, it is worth checking the surrounding hardware rather than blaming the new part straight away.
When DIY makes sense – and when it does not
For a standard passenger car boot or bonnet with accessible fittings, replacing gas struts can be a manageable DIY task. If you are comfortable using basic tools and can secure the panel safely, it is often a simple job.
Where things get more complicated is with heavier tailgates, aftermarket canopies, custom installations or worn mounting points. In those cases, force rating and fit become more critical, and the risk of damage or injury is higher if something is off. If you are unsure, professional replacement can save time and prevent the wrong part being fitted.
That is especially relevant if convenience matters. For many drivers, arranging a mobile service is easier than balancing a tailgate with a timber prop in the driveway and hoping the replacement struts are right.
Why proper replacement matters
Gas struts are easy to overlook because they are small, but they do an important job every day. A weak strut affects safety, convenience and the feel of the vehicle. It can also lead to cracked trims, damaged hinges and unnecessary wear if a panel is constantly dropping or being forced open.
Done properly, replacement restores smooth operation and gives you confidence that the bonnet, boot or canopy will stay where it should. That is the difference between a quick fix and a proper result.
For vehicle owners who want dependable workmanship without paying over the odds, having the job handled professionally can be the more practical option. VIP Car Care offers mobile gas strut replacement, which means the work can be done at a location that suits you, with the reassurance of experienced operators who understand the right fit for the job.
If your boot, bonnet or tailgate has started falling short, do not wait for it to fail completely. Replacing tired gas struts early is one of those small maintenance jobs that makes your vehicle safer, easier to use and better cared for every day.
