Parts for your 2021 Mitsubishi Asx-Gas struts

2021 Mitsubishi ASX gas struts — what they do and how to look after them

Gas struts are fitted to the 2021 Mitsubishi ASX on the rear tailgate (back door). This is confirmed in Mitsubishi technical documentation that specifies gas-filled lift supports for the back door in the Body/Back Door section of the Mitsubishi Motors Service Manual (RVR/ASX/Outlander Sport platform), and in the 2021 ASX Owner’s Manual where the back door is shown supported by dampers while the bonnet uses a manual prop rod. Major aftermarket catalogues such as Stabilus LIFT-O-MAT and Monroe Max-Lift also list rear lift supports for ASX model years spanning 2010–2021. So gas struts are relevant to servicing the tailgate on a 2021 ASX, while the bonnet typically does not use them.

On the ASX, those gas-charged struts take the weight of the tailgate, control the opening speed and hold it safely at full height. They make loading the boot a breeze and stop the hatch from thumping or drifting down on a windy day.

As with any pressurised component, gas struts are a wear item. The seals age, the nitrogen charge slowly drops, and cold weather can knock a bit of punch out of them. A quick check at each service is smart: open the tailgate and ensure it lifts smoothly, holds at full extension and doesn’t sag. Any hissing, binding, or an oily film on the rod is a red flag.

Replacement is straightforward and usually a driveway job. The golden rules are to support the tailgate securely (it’s heavier than it looks) and to replace struts in pairs so the load stays balanced. Most ASX struts clip on and off ball studs with a small retaining spring—no need to unbolt the hinge or muck around with alignment. Once fitted, give the joints a gentle clean and make sure the clips are fully seated.

To help them last, avoid using the tailgate as a handle to pull the vehicle around, keep the exposed rods clean, and be mindful that performance will feel a bit softer in frosty conditions. There’s no set kilometre interval for replacement, real-world lifespan is typically 4–8 years depending on climate and use. If the hatch won’t stay up, or opens too slowly, that’s the cue to swap them out.

• Inspect at each service or every 10,000–15,000 km.
• Replace in pairs, support the tailgate during work.
• Watch for oil mist, slow lift, or any drop from full height.

Do the 2021 ASX bonnet struts exist?

Most 2021 ASX variants use a prop rod for the bonnet rather than gas struts, as noted in the Owner’s Manual. Bonnet strut retrofit kits are available in the market, choose a vehicle-specific kit and install with care if going that route.

How can an owner tell if their 2021 Mitsubishi ASX gas struts are failing?

Common signs are a tailgate that opens slowly, won’t stay fully up, or drops in a breeze. Oil on the strut rod, noisy operation, or needing to “help” the hatch lift are also giveaways. If any of that shows up, it’s time for a pair of new struts.

Can ASX tailgate gas struts be replaced at home?

Yes. Support the tailgate safely with a prop or a helper, flick the retaining clips off the ball joints, pop the old struts off, then snap the new ones on. Replace both sides together and check the hatch opens and holds at full height before calling it done.

Does the 2021 ASX have bonnet gas struts from factory?

No. The bonnet is held with a prop rod on most 2021 trims. Owners keen on hands-free lifting can fit an aftermarket bonnet strut kit designed for the ASX, using corrosion-resistant hardware and the factory mounting points where provided.