Parts for your 2021 Subaru Outback-Gas struts

2021 Subaru Outback gas struts — purpose, checks and replacement

Per Subaru’s technical literature for the sixth-generation Outback (MY2020–MY2022)—including the Owner’s Manual sections on the rear gate/power rear gate and the body service information—the vehicle is fitted with gas‑charged support struts on the rear tailgate. Parts catalogues list these as liftgate support struts (manual rear gate uses two gas struts, power rear gate variants pair a powered actuator with a gas strut). The bonnet on most trims uses a prop rod rather than gas struts.

On a 2021 Subaru Outback, the gas struts do the heavy lifting for the rear gate. They counterbalance the weight of the tailgate, control its opening speed and keep it safely up while loading the boot. On power tailgate models, the gas strut works alongside the drive unit to smooth out motion and reduce load on the motor.

Over time, seals wear and the nitrogen charge drops, especially with Aussie and Kiwi heat, coastal air and dust. That’s when the tailgate can feel heavy, struggle to rise, or sag unexpectedly—never ideal with arms full of shopping or the pram halfway in.

• Common signs they’re due: tailgate won’t stay up, opens unevenly, feels “jerky,” or leaves a light oil film on the rod.
• Safety tip: don’t rely on a weak strut—support the gate before any checks.

For servicing, it’s smart to inspect the struts annually. Look for smooth operation, clean chrome rods and intact end fittings. If replacement’s needed, it’s best practice to change them in pairs on manual gates to keep lift balanced. On power rear gates, follow the Subaru procedure—one side may be a powered actuator. After fitting, the power gate may need an initialisation/calibration cycle as outlined in Subaru service info.

Fitment pointers: support the tailgate securely, swap one side at a time, avoid twisting the body brackets, and clip the ball‑sockets fully home. Don’t try to “re‑gas” them—these are sealed units and are replaced, not refilled.

Light maintenance helps: keep the rods clean with a soft cloth, avoid silicone sprays on the shaft seals, and don’t use the strut as a grab handle. With quality OEM or equivalent struts, owners can expect reliable service for years—typically 4–8 years depending on climate and use.

Do all 2021 Outbacks have gas struts?

Yes for the rear tailgate—every 2021 Outback uses gas support for the rear gate. Most trims use a prop rod for the bonnet, so bonnet gas struts generally aren’t fitted from factory.

How long do the rear gate gas struts last?

In local conditions, many last 4–8 years. High heat, frequent use and coastal air can shorten life. If the tailgate sags or opens sluggishly, it’s time to test and likely replace—ideally as a pair on manual gates.

Can gas struts be re‑gassed, or do they need replacing?

They’re sealed units, so proper practice is to replace them. “Re‑gassing” isn’t recommended and rarely holds up. Quality replacements offer the safest, most reliable fix.