How to Replace Trunk Lid Lift Support: DIY Guide

A failing trunk lid lift support—also called a trunk strut or gas spring—can turn a simple task like loading groceries into a frustrating struggle. This intermediate DIY repair typically takes 1–2 hours and can save you $150–$300 in labor costs at a dealership or independent shop. However, these instructions provide general guidance only. Specific tools, torque specifications, fastener sizes, and removal procedures vary significantly by vehicle make, model, and year. You must consult your vehicle's service manual for exact specifications, step sequences, and any vehicle-specific precautions before beginning. If you're not comfortable working with pressurized components or suspension-related body work, have a qualified mechanic perform or inspect this repair.

What You'll Need

Tools

• Socket set and wrench set (metric and standard, as applicable to your vehicle)
• Torque wrench (essential for fastener specifications)
• Screwdriver set (Phillips and flathead tips)
• Pry bar or trim panel removal tool (helps disconnect any clips or brackets)
• Jack and jack stands (if the vehicle must be lifted for access)
• Work light or headlamp (many trunk spaces have limited lighting)
• Safety glasses and gloves

Some vehicles may require additional specialty tools such as offset wrenches or socket extensions to access tight mounting points. Check your service manual for any vehicle-specific tool recommendations.

Parts & Materials

• Replacement trunk lid lift support (gas strut or pneumatic strut)
• New fasteners—bolts, washers, and clips (do not reuse old fasteners)
• Penetrating oil (for corroded fasteners)
• Clean rags or paper towels

When selecting a replacement support, look for units with a corrosion-resistant coating suitable for underbody exposure. Stainless steel or zinc-plated fasteners are preferable to plain steel, especially in regions where road salt is used. Match the lift force (measured in pounds or newtons) to your vehicle's original specification—this information is typically found in the service manual or on the original support's label.

Before You Begin

• Trunk lid lift supports are pressurized gas components and can cause injury if mishandled. Never attempt to disassemble, depressurize, or modify a damaged support. Work in a well-ventilated area and wear safety glasses at all times. Keep your hands and face clear of the support during removal and installation.
• Park on level ground, turn off the engine, and fully open the trunk lid. Keep the lid open throughout the entire repair. If you must lift the vehicle, place it securely on jack stands—never work under a vehicle supported only by a hydraulic jack.
• Check local regulations for disposal. Some jurisdictions classify pressurized gas struts as hazardous waste and require special handling. Do not attempt to depressurize the old support yourself; contact a local waste facility or auto parts retailer for proper disposal guidelines.
• If you are not experienced with suspension or body component repairs, or if you are uncomfortable working with pressurized components, have this repair performed or inspected by a qualified mechanic. A faulty trunk lid support can cause the lid to fall unexpectedly, creating a serious safety hazard.

Step-by-Step: How to Replace Trunk Lid Lift Support

1. Open the trunk lid fully

   Raise the trunk lid to its maximum height. If your vehicle has a built-in prop rod, engage it to hold the lid open. If not, use a rigid support such as a wooden dowel or specialized trunk prop to prevent the lid from closing unexpectedly during your work. This is a critical safety step.

2. Locate the lift support attachment points

   Examine both ends of the lift support. One end bolts to the underside of the trunk lid; the other bolts to the vehicle's body frame or rear quarter panel. Take clear photos of the original support installation, including the orientation of the rod and the angle at which it sits. These photos will serve as your reference for proper installation of the new support. Also note the exact location of any brackets, clips, or fasteners.

3. Remove fasteners at the trunk lid attachment point

   Using the appropriate socket or wrench size, unbolt the support from the underside of the trunk lid. If fasteners are corroded or stubborn, apply penetrating oil and allow it to soak for 10–15 minutes before attempting removal. Work slowly to avoid stripping the bolt head. Keep all fasteners in a container so you don't lose them. If any fastener is damaged, stripped, or corroded beyond reuse, it should be replaced with new hardware.

4. Remove fasteners at the body frame attachment point

   Using the same technique, unbolt the support from the vehicle frame or body attachment point. Body attachment points are often in tight or awkward spaces; you may need a short wrench, socket extension, or offset wrench to reach them. Apply penetrating oil if needed and work carefully to avoid damage to the surrounding components. Replace old fasteners with new ones.

5. Carefully extract the old lift support

   Once both fasteners are removed, gently pull the old support free from its mounting points. Avoid sudden jerking or twisting motions, as this can damage brackets or attachment points. Dispose of the old support according to your local waste regulations—do not attempt to deflate or disassemble it yourself.

6. Inspect mounting brackets and attachment points

   Examine the mounting brackets on the trunk lid and frame for visible cracks, severe corrosion, bent flanges, or other damage. If brackets are compromised, they should be repaired or replaced before installing the new support. Use a clean rag to wipe away any dirt, rust flakes, or debris from attachment points. If corrosion is heavy, gently scrub with a wire brush or fine steel wool to ensure fasteners will seat properly.

7. Align and position the replacement lift support

   Position the new support so that both the rod end (trunk lid end) and the base end (frame attachment) align perfectly with their respective mounting points. Compare the support's orientation to the photos you took in Step 2. Some supports have direction markings or arrows embossed on the body indicating the correct installation direction. Ensure the support is not twisted and sits at the same angle as the original.

8. Install fasteners at both attachment points

   Insert new fasteners (bolts, washers, and any clips) into both the trunk lid and body frame attachment points. Hand-tighten all fasteners first to ensure proper alignment of the support before applying torque. Once aligned, you will torque each fastener to the exact specification listed in your vehicle's service manual. Consult your manual—torque specifications vary by vehicle and are critical for safety. Over-tightening can strip threads or crack mounting brackets; under-tightening can lead to vibration and loosening over time.

9. Verify operation and torque all fasteners to specification

   Gently open and close the trunk lid several times to ensure the new support operates smoothly and the lid lifts and closes without sagging, sticking, or drifting. Once you've confirmed smooth operation, use a torque wrench to tighten all fasteners to the exact torque specification from your vehicle's service manual. This step is essential for long-term reliability and safety.

10. Test full range of motion and inspect for leaks or issues

    Open the trunk fully and verify that the lid lifts completely without resistance. Close the trunk and confirm it shuts smoothly and latches securely. Inspect the new support for any visible signs of gas leakage (usually a fine mist or oily residue on the rod), cracks, or damage. If the lid sags, drifts closed, requires excessive force to open or close, or shows any signs of leakage, stop immediately and consult a professional mechanic before using the vehicle.

Tips for a Successful Trunk Lid Lift Support Replacement

• Document the original installation with photos. Before you remove the old support, take clear, close-up photos of both attachment points and the overall orientation of the support. These images are invaluable if you get confused during installation or need to compare angles and alignment.
• Always replace fasteners with new hardware. Even if old bolts or clips appear reusable, use new fasteners. Old hardware is more susceptible to corrosion and may not maintain proper torque over time, leading to vibration and potential safety issues. OEM-equivalent or stainless steel fasteners are preferable.
• Use the correct torque specifications. Underbody components must be properly torqued to prevent loosening caused by vibration and road conditions. Consult your service manual for exact torque values; do not guess or estimate. A torque wrench is a worthwhile investment and takes the guesswork out of this critical step.
• Be patient with corroded fasteners. If bolts are severely corroded or stuck, apply penetrating oil, wait 30 minutes, and gently work the fastener free using increasing socket sizes or a bolt extractor. Rushing this step risks damaging the mounting brackets or threads, which may require costly repairs.

When to Call a Professional

Stop and contact a qualified mechanic if you encounter any of the following: mounting brackets that are cracked, severely corroded, or bent; fasteners that are stripped, broken, or cannot be removed without risking damage to attachment points; a trunk lid that does not operate smoothly after you've installed the new support (sagging, drifting, or requiring unusual force); or uncertainty about torque specifications, fastener types, or proper installation procedure. The trunk lid is a safety-critical component, and a failing support can allow the lid to drop unexpectedly on occupants or pedestrians. If you are not experienced with suspension or body component repairs, or if you feel uncomfortable at any point during the process, having a professional mechanic perform or inspect this repair is the safest choice. A professional can also verify that fasteners are torqued to exact specifications and that the support operates properly.