Parts for your 2021 Mazda 3-Gas struts

2021 Mazda 3 gas struts: what’s fitted and how to look after them

Per Mazda technical sources, gas struts are fitted to the 2021 Mazda 3 hatchback tailgate, but not to the bonnet or the sedan’s boot. The 2021 Mazda 3 Owner’s Manual (BP series) describes bonnet support with a prop rod, and the Workshop Manual (Body – Rear) covers the “Liftgate Stay Damper” used on hatch models. Mazda’s Electronic Parts Catalogue for BP hatchback also lists the liftgate stay/damper assemblies. The sedan boot uses torsion bars and hinges rather than gas struts.

On the hatch, those gas struts (stay dampers) do the heavy lifting—literally. They counterbalance the tailgate’s weight so it opens smoothly, holds its position, and closes with predictable effort. That’s not just about convenience, it also reduces strain on hinges and helps prevent the tailgate from slamming in wind or colder weather.

Like any pressurised component, struts gradually lose charge and damping oil over time. When that happens, the tailgate may rise sluggishly, fail to stay up, or drop unexpectedly—none of which is ideal when loading the weekly shop. Tell-tale signs include:

• Needing a helping hand to lift or keep the tailgate open
• Notchy or uneven movement
• Audible hissing or visible oil misting around the rod seals

Replacement is straightforward and usually done in pairs to keep lift balanced. Use a prop or a second person to support the tailgate, then swap each strut by releasing the retaining clips at the ends. Always match the BP-series hatch spec for length, end fittings, and force rating—going stiffer or softer can affect latch alignment and closing effort.

Care is simple and low-effort:

• Keep the chrome rods clean, wipe off dirt and road film so the seals aren’t abraded.
• Don’t grease the rods—lubricants attract grit and can damage seals.
• Avoid using the tailgate as a handle to pull the car forward in tight parks, side loading can tweak the joints.
• If a strut shows oil weep or the tailgate won’t hold, book a replacement rather than waiting for a cold morning surprise.

For sedan owners: it’s normal not to see gas struts in the boot, and the bonnet on all 2021 Mazda 3 variants uses a prop rod by design.

Popular questions

Does the 2021 Mazda 3 sedan have gas struts?
No. The sedan’s boot uses torsion bars and conventional hinges, and the bonnet has a prop rod. Only the hatchback’s tailgate is equipped with gas struts (stay dampers). That’s why hatch owners will notice the tailgate self-lifting, while sedan owners won’t.

How long do the Mazda 3 hatch gas struts last?
Typically 5–10 years, depending on climate and use. Frequent hot–cold cycles, salt air, and dust can shorten life. If the hatch won’t stay up, needs help to open, or the struts show oil misting, it’s time to replace them—ideally as a pair to keep lift even and predictable.

Can bonnet gas struts be added to a 2021 Mazda 3?
Yes, aftermarket bonnet-strut kits are available. Choose a BP-series specific kit with proper brackets so there’s no drilling into structural areas. Check that the bonnet clears at full lift and that the kit doesn’t foul washer lines. If under warranty, ask your dealer about accessory fitment guidance first.