Parts for your 2015 Mazda Cx-9-Gas struts

2015 Mazda CX-9 gas struts — what they do and when to replace them

Technical sources confirm the 2015 Mazda CX-9 is fitted with gas-charged support struts on the rear liftgate. The Mazda workshop manual for the first‑generation CX‑9 (Body: Liftgate section) details removal/installation of the liftgate stay assemblies, and the Mazda electronic parts catalogue lists these gas springs as serviceable items. The bonnet on this model uses a prop rod rather than gas struts. Owner’s manual notes for power liftgate variants also reference the liftgate supports working with the motor.

Those rear gas struts do the heavy lifting, counterbalancing the tailgate’s weight so it opens smoothly and stays put overhead. They’re sealed, nitrogen‑charged units with internal oil for damping, so you get a calm, controlled motion rather than a wobble or slam. Whether the CX-9 has a manual or power liftgate, the struts carry the load and protect hinges and the latch from shock.

Like any sealed component, they wear. Seals harden, gas pressure tails off, and cold weather can make weak struts feel even lazier. Common tell‑tales include the liftgate creeping down on your head, needing two hands to heave it up, or a slow, uneven rise.

• Liftgate won’t stay fully open, or sags in a breeze
• Needs more effort to lift, or opens sluggishly
• Oil mist on the rod, pitting or rust on the chrome
• Power liftgate works but strains or stops partway

For servicing, the best practice is to replace struts in pairs, matching the correct force rating for the CX-9. Swapping only one can twist the tailgate and overwork hinges. Support the liftgate securely with a prop or a mate before releasing the spring clips, the strut can extend with a fair bit of force. If ball studs are removed, torque them to spec from the workshop manual and check the latch alignment after.

There’s no routine “re‑gassing” or lubrication—gas struts are sealed. Keep the chrome rod clean, don’t paint it, and avoid silicone or petroleum sprays that can attack the seals. If you’ve added a heavier spoiler, glass, or accessories to the tailgate, consider uprated struts. In normal Aussie and Kiwi conditions, many owners see 5–8 years before performance drops off enough to warrant replacement.

FAQs

Does the 2015 Mazda CX-9 have bonnet gas struts?
No. The bonnet uses a prop rod. Gas struts are fitted to the rear liftgate only, including vehicles with the power liftgate option where the motor works alongside the struts.

How often should CX-9 liftgate struts be replaced?
There’s no fixed interval—replace when symptoms appear. As a guide, many see 5–8 years depending on climate and usage. If the tailgate sags, opens slowly, or the rods show oiling or pitting, it’s time.

Can they be replaced at home?
Yes, with basic tools. Support the tailgate safely, flick the retaining clips, and swap the struts—ideally in pairs. If unsure about ball-stud torque or alignment, a workshop can sort it quickly.