How to Replace a Tailgate Lift Support: DIY Installation Guide

Tailgate lift supports are hydraulic or pneumatic struts that hold your tailgate open and help lower it smoothly when released. Over time, they lose pressure and fail to support the weight of the tailgate, forcing you to prop it open manually or letting it slam shut. Replacing one or both supports is a beginner-to-intermediate repair that typically takes 30–45 minutes per side. These instructions are general guidance; specific tools, torque specifications, mounting locations, and procedures vary significantly by vehicle make, model, and generation. Before starting, consult your vehicle's service manual for exact fastener sizes, torque values, and any model-specific steps. If you're unsure about any procedure or lack experience working with structural components, have a qualified mechanic inspect or perform the replacement.

What You'll Need

Tools

• Socket set and ratchet wrench (typically 8 mm to 13 mm sockets)
• Torque wrench (to tighten fasteners to specification)
• Jack and jack stands or vehicle lift (to safely support the tailgate)
• Screwdriver set (for prying or removing clips)
• Adjustable wrench or open-end wrenches
• Work light or flashlight (mounting areas can be dark)
• Shop towels or rags (to clean old grease or debris)

Parts and Materials

• Replacement tailgate lift support assembly (one or two, depending on condition)
• Replacement fasteners or bolts if originals are damaged or corroded
• Anti-seize compound or thread-locking compound (as recommended by service manual)
• Lubricating grease or silicone spray (optional, for smooth operation)

Before You Begin

• Safety First: Park on level ground and engage the parking brake. Never work under a tailgate supported only by a failing lift support. Use a tailgate support prop, wooden block, or jack stand to hold the tailgate securely open at a comfortable working height. This prevents it from falling and causing injury or damage.
• Gather Tools and Parts: Lay out all tools and fasteners in your work area before beginning. A clean, organized workspace reduces the risk of losing small bolts and makes the job faster. Ensure adequate lighting, as mounting brackets are often in shadowed areas.
• Battery Disconnect (If Applicable): If your vehicle has electronic tailgate features—such as power-close or automatic-locking functions—disconnect the negative battery terminal before starting work. This prevents accidental actuation or electrical short circuits during removal and reinstallation.
• Know When to Stop: Tailgate lift supports are structural components that directly affect vehicle operation and safety. If the mounting brackets are cracked, severely corroded, or show signs of collision damage, do not attempt the repair yourself. Instead, have a qualified mechanic evaluate the damage and perform the replacement. If you are inexperienced with structural or suspension work, consult a certified technician to inspect your work before returning the vehicle to service.

Step-by-Step: How to Replace a Tailgate Lift Support

1. Prepare and Support the Tailgate. Open the tailgate fully and position your support prop, wooden block, or jack stand underneath to hold it securely. Adjust the height so the tailgate is comfortable to work around and will not drop if the support slips. Double-check stability before proceeding.
2. Locate the Lift Support Mounting Points. The tailgate lift support is typically mounted at the upper corners or upper sides of the truck bed, securing the top of the tailgate opening. Look for a cylindrical metal rod or strut with bolts on each end. One end usually bolts to the tailgate frame, and the other end bolts to the bed wall or frame. Identify both attachment points before beginning removal.
3. Remove the Old Lift Support. Using a socket wrench or adjustable wrench, unbolt the fastener(s) at one end of the lift support—typically the bed or frame end first. Set the bolts aside in a labeled container. Then unbolt the opposite end from the tailgate. Gently remove the old lift support and inspect the fastener holes and brackets for damage, corrosion, or debris.
4. Inspect Mounting Brackets and Hardware. Visually examine the mounting brackets, bolt holes, and surrounding areas for cracks, rust, or stripped threads. Wipe away old grease, dirt, or corrosion with a shop towel. If fastener holes are corroded or threads are damaged, clean them carefully. If threads are severely stripped, consult your service manual for repair procedures or seek professional help. Apply a light coat of anti-seize compound to fastener threads if your service manual recommends it.
5. Install the New Lift Support. Align the new lift support with the mounting holes. Insert bolts by hand (or hand-tighten clips if the design uses them) to hold the support in position. Ensure the support is seated flush against the mounting brackets and is not twisted or misaligned. Do not tighten fasteners fully at this stage.
6. Tighten Fasteners Securely. Using a socket wrench and torque wrench, tighten fasteners in a cross or alternating pattern (e.g., top bolt, then bottom bolt, then back to top if there are multiple bolts). Tighten to the torque specification listed in your vehicle's service manual—over-tightening can crack plastic mounting tabs or strip threads, while under-tightening risks the support coming loose. If your manual specifies a tightening sequence, follow it exactly.
7. Test Tailgate Operation. Carefully lower the support prop and allow the tailgate to rest against the new lift support. Raise and lower the tailgate by hand several times, checking for smooth operation and proper support at all angles. The tailgate should not drop suddenly, bind, or make unusual sounds. If resistance or noise occurs, stop and inspect the installation.
8. Reconnect Battery and Verify Electronics (If Applicable). If you disconnected the battery earlier, reconnect the negative terminal. If your vehicle has a power tailgate or electronic locking mechanism, test it to confirm all functions operate normally. Close the tailgate fully and verify it locks or latches properly.

Tips for a Successful Tailgate Lift Support Replacement

• Use a Reliable Support System: Never rely on a failing lift support or a makeshift prop to hold the tailgate during work. Invest in or borrow a proper tailgate support rod, adjustable prop, or jack stand. A falling tailgate can cause serious injury and expensive damage.
• Do Not Over-Tighten: Fastener over-tightening is a common mistake that cracks plastic mounting brackets or strips bolt holes, especially on older vehicles. Consult your service manual for the correct torque value and use a calibrated torque wrench. If a bolt feels very tight before reaching the specified torque, stop and inspect the threads.
• Replace Both Supports Simultaneously: Tailgate lift supports typically wear together over the same mileage. If one support is failing, the other is usually near the end of its service life. Replacing both at the same time ensures balanced support, even operation, and avoids a return trip to replace the second support shortly after the first repair.
• Organize Your Fasteners: Keep all bolts, clips, and fasteners in a labeled container as you remove them. This prevents confusion during reinstallation and ensures you use the correct hardware in the correct location, which is especially important if fasteners vary by size or type.

When to Call a Professional

Do not attempt this repair if the tailgate is bent, cracked, or shows signs of impact damage. Similarly, if the mounting brackets on the truck bed or frame are cracked, heavily corroded, or deformed, this work requires professional evaluation and possible structural repair. If you see rust that has eaten through the bracket material or if fastener holes are severely stripped and cannot be cleaned up, these are red flags that your vehicle needs a qualified mechanic's assessment. Tailgate lift supports are safety-critical components—they help support the tailgate structure, control its movement, and contribute to overall vehicle integrity. If you are unsure about any step, lack mechanical experience, or have doubts about the installation after completion, do not put the vehicle back into service. Instead, have a certified mechanic inspect the repair and verify that fasteners are torqued correctly, the support operates smoothly, and no structural damage was missed. Verification by a qualified technician ensures your safety and the long-term reliability of your tailgate system.