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.

Belarus budget

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.