Tesla S/X/3/Y: frunk and trunk gas struts, when to replace and what to fit

Summary

Gas struts (lift supports) are sealed nitrogen cylinders that hold the frunk lid and tailgate open. They die quietly: the frunk lid no longer rises all the way to the stop, the powered trunk "folds back" halfway through travel. The part is cheap (from $25 a pair), replacement on 3/Y/S without power liftgate is a 15-minute job by hand. On S/X with power liftgate and Y with power liftgate, the gas struts work in parallel with the actuator, so a dead gas spring can masquerade as an "actuator glitch".

Symptoms / diagnosis

• Frunk lid won't open all the way, needs hand-pulling to the stop.
• In the cold it drops back down, especially if released.
• Powered trunk closes back when opening halfway (after calibration and actuator check it still does).
• Weak return when raising: moves softly, then drops sharply at the end of travel.
• Visible oil traces on the rod (rare but happens).
• Power off the car and lift the lid by hand: it won't hold at the top, it slowly drops.

What to do

1. Simple test. Open the frunk/trunk fully and release: it should hold without help. If it drops 5–10 cm or more in a minute, the gas is gone, replace.

2. Sizes and what to buy.

Better to verify dimensions with a caliper on the original part before ordering.

1. Brands and types.

• OEM Tesla: a copy of a typical inexpensive gas strut, no special reason to overpay.
• Stabilus / Suspa / Lesjöfors: European brands used as replacements, the most reliable among non-OEM.
• Pneumatic auto-open (EVANNEX, Abstract Ocean, TAPTES, Arana): heavy-duty gas struts for the frunk that open the hood from a button. Convenient, but they last less than stock (1–2 years) because of the higher force.
• AliExpress: fine if branded (CTR/Suspa copies). Unbranded may come with different L/R force and skew the frunk. Always buy as a pair from one manufacturer.

From the chat (#224419, #224425): on cars at 150k+ km, original gas struts often die, and people confuse this with an actuator problem. Check gas struts first.

Cost (Minsk shop prices)

Parts:

• A pair of OEM/quality aftermarket (Stabilus/Suspa) struts for frunk or trunk: $30–80.
• Pneumatic auto-open kit (EVANNEX/TAPTES) for frunk: $26–55 (motorized power-frunk kits at $250–400 are a different class).
• AliExpress pair: $15–35 (branded) / $8–15 (unbranded).

Labor (Minsk, ~$50/h):

• Replacing a pair of frunk/trunk struts on 3/Y/S without power: 0.3–0.5 h → ~$15–25.
• On Y/S/X with power liftgate, with trim removal and calibration: 0.7–1.5 h → ~$35–75.
• Auto-open kit installation: 0.5–1.0 h → ~$25–50 (plus wiring/setup sometimes).

Total range:

• Minimum (3/Y frunk, budget, DIY): $25–35.
• Average (quality pair + labor): $60–120.
• Auto-open kit with installation: $50–105.
• On S/X with power liftgate, if gas strut is replaced + actuator is fixed: up to $250+ (the actuator can be a separate line item).

DIY notes

• On the frunk: open it, prop with a wood stick (don't hold by hand!), then pry the metal retainer clip at the top of the strut with a thin plastic pry tool/screwdriver and lift it off the ball stud. Bottom the same.
• Install the gas strut rod-down, for seal lubrication. This is a rule for any automotive gas strut.
• Replace as a pair only: one new + one old = lid skew + quick death of the new one.
• On the powered trunk, first raise it fully on the actuator, then disconnect 12V (negative terminal), prop the tailgate with a wood block/telescoping pole, and only then remove the strut. Without a prop, a de-powered actuator won't hold the heavy tailgate: it will sag and come down on your head or bend the hinges.
• Tailgate calibration on Model Y and S after replacement: open-close fully a few times from the button, and the car re-learns the limits.
• Don't confuse the gas strut with the spoiler on Model X: that's a power rear tailgate spoiler, a separate story.
• On the auto-open frunk: check that the rubber stops on the lid are intact; without them the lid will rattle against the body.

Links / sources

• Tesla Service, Replacing Hood Struts: https://service.tesla.com/docs/Public/diy/model3/en_us/GUID-9EE66108-F5F4-4F26-BA6E-DD6ACA347785.html
• Tesla Service, Replacing Trunk Struts (Non-Powered): https://service.tesla.com/docs/Public/diy/model3/en_us/GUID-1D824F2F-82DE-4547-A4FD-88607361CC5D.html
• Tesla DIY Repair, Frunk Strut Replacement (All Models): https://tesladiyrepair.com/posts/tesla-frunk-strut-replacement/
• Youcanic, Tesla Front Trunk Frunk Lift Strut Replacement: https://www.youcanic.com/tesla-front-trunk-frunk-lift-strut-replacement-upgrade/
• TMC, FRUNK Strut Replacement: https://teslamotorsclub.com/tmc/threads/frunk-strut-replacement.243514/
• YouTube, Upgrade the front trunk struts in Tesla Model 3: https://www.youtube.com/watch?v=wIQ5GyzOJgg
• Hansshow, Tesla Model S Power Frunk (aftermarket kit): https://www.hansshow.com/products/tesla-model-s-power-frunk
• EVANNEX, Frunk Lift For Tesla Model 3 (auto-open prices): https://evannex.com/products/frunk-lift-for-tesla-model-3

Community experience

From the TESLA owner's group BELARUS chat: gas struts are a common nuisance, especially on high-mileage S 2014–2018.

Additional observations:

1. On an S at ~160k mileage the original gas struts won't open the hood fully, but if you help by hand at the start of travel they reach. That's already a signal to replace (#224419).
2. Sometimes stronger gas struts are fitted instead of a power frunk: "the cheaper option vs the actuator" (#224425).
3. Complaint on a 2022 M3: the powered trunk closes halfway when opening. Replaced the mechanism, checked the strut (was fine), calibrated, and the glitch remained (#372570). The strut is the first hypothesis but not the only one.