Rear hatch damper installation instructions for a precise fit

A tailgate that drops, will not stay open, or needs a shoulder push to reach its full height most often has worn gas struts. The repair itself is usually quick, but a guide to installing tailgate struts should start with fitment, not tools. Gas springs that look similar can differ in extended length, stroke, mounting ends, damping, and extension force. An incorrectly matched pair may hold the tailgate too low, put excessive strain on the hinges, or fail to hold the tailgate open at all.

W For vehicles with a heavy tailgate, spoiler, spare-wheel carrier, opening window, or powered lift system, choosing the right part is even more important. Before placing an order, verify the make, model, year, body style, and original part number. W In European cars, a production change during the model year or a different tailgate option may mean that a completely different strut is required.

Before you begin: Make sure you have the correct tailgate struts

A tailgate strut, also called a gas spring, telescopic strut, or gas shock, is designed for a specific load and mounting geometry. Do not choose a replacement based only on length or a generic product description. Read the reference number printed on the old strut and compare its extended and compressed lengths, mounting type, and extension force in newtons (N), if specified.

OEM and original-equipment-quality struts are a sensible choice when precise fitment is essential. A strut with too little force can cause the tailgate to drop on its own in freezing weather. In contrast, a strut with too much force will make the tailgate difficult to close and put unnecessary strain on the hinges, body mounts, and latch components. Always replace both struts at the same time. If one has lost pressure, the other has experienced the same age, weather exposure, and number of operating cycles.

Check whether your vehicle has standard gas struts or an electric liftgate system. Electric struts may contain wiring, screw motors, position sensors, or dedicated modules. They are not serviced in the same way as conventional gas springs. Never disconnect electric liftgate components while the system is active, and follow the model-specific repair procedure if electric struts are installed.

Tools and safety

Most conventional struts mounted on ball studs require only a small flathead screwdriver or pick. W some vehicles use mounting bolts, threaded studs, or clips that require a socket set, a torque wrench, and trim removal tools. It is helpful to have a clean cloth on hand to wipe dirt from the mounting points.

Solid support is essential. Use a dedicated trunk lid support, a suitably cut piece of lumber with a nonslip end, or ask another person to hold the lid firmly. Do not rely on a single worn strut to hold the lid while you remove the other one. The lid could drop suddenly, damaging the paint, shattering the glass, or causing injury.

Park the car on level ground and open the trunk lid fully. If the vehicle is on a slope, the lid’s opening angle and load may change while the struts are being removed. Avoid working in strong winds. A gust could jerk the unsupported lid sideways and damage the hinge or the ball stud on the body.

Trunk lid strut installation guide: Removal and replacement

Start on one side. Leaving the old strut on the opposite side helps keep the hatch in position while it is supported. Place the support under a strong, stable part of the trunk lid, not on the trim, glass, plastic spoiler, or thin inner sheet metal.

Carefully release the retaining clips

Most gas struts are attached to ball studs with a steel spring clip in each socket. Look closely before inserting a tool. The clip usually needs to be bent outward by only a few millimeters. You usually do not need to remove it completely.

Use a flathead screwdriver to gently pry and pull the clip out of the groove in the socket. Once released, slide the actuator socket straight off the ball stud. Do not pry against the painted bodywork or twist the stud. If the socket is difficult to remove, hold the actuator body and apply steady pressure instead of striking it.

Remove the upper or lower end first, depending on access, then release the other end. Note the installation direction before fully removing the strut. W many vehicles, the thicker cylinder is at the top and the piston rod points downward when the tailgate is closed. This position helps protect the piston rod seal and keeps it properly lubricated, but the vehicle's factory design always takes precedence.

Compare the new and old parts

Before snapping the new strut into place, compare it directly with the removed part. Check the overall length, mounting ends, socket depth, piston rod diameter, and part numbers. If the new part is visibly longer or shorter, or has a different fitting, stop and do not force it into place.

Check both ball studs for corrosion, looseness, or damaged threads. A loose stud can cause symptoms similar to a worn strut and may cause it to detach. Wipe light dirt off the ball surface with a cloth. Do not apply grease, oil, or penetrating fluids to the gas strut piston rod. Contamination can damage the seal and shorten the part's lifespan.

Install the new gas strut

Align the new socket with the ball stud and press it on perpendicularly until it clicks onto the ball. You should not need to remove the retaining clip completely. Make sure the clip is back in its locked position and that the socket cannot be pulled off by hand.

Install the other end in the same way. If the tailgate has shifted slightly while supported, adjust the support height or ask someone to gently move the tailgate into position. Never use a gas strut as a lever to straighten or force the tailgate into position.

Repeat the entire process on the other side. After installing both struts and ensuring that all clips are properly seated, slowly remove the support. Keep your hand on the tailgate during its first downward movement, in case the part is incorrect or the fitting has not fully clicked into place.

Check the tailgate operation before driving

Open and close the tailgate several times. It should rise smoothly, reach its intended open height, and stay up without dropping on its own. The force needed to close it should be moderate and controlled. Listen for knocking, rubbing, or the socket moving loosely on the ball stud.

Check the clearance when fully open. The tailgate should not hit the garage door, roof-rack accessories, a rear-mounted bike rack, or other obstacles. If the new struts raise the tailgate noticeably higher than before, verify the part number instead of assuming that stronger operation is an advantage.

Low temperatures temporarily reduce the performance of gas springs. A correctly selected strut may operate more slowly in winter, especially on a large SUV tailgate. However, it should still safely hold the tailgate open. If new struts don’t hold the tailgate up right away, check whether it has extra equipment adding weight, whether water has accumulated inside, whether the hinges are damaged, or whether the wrong part was installed.

The most common installation mistakes that cause repeat failures

The most common mistake is replacing only one strut. The new component takes most of the load while the worn one continues to weaken. Replacing the pair ensures even lifting force and predictable operation of the entire mechanism.

Another issue is mixing up struts intended for the left and right sides. Many conventional struts are interchangeable between sides, but not all. Some models require different lengths, extension forces, or mounts depending on the side. This is especially important for split tailgates, opening rear windows, and vehicles with asymmetrical equipment.

Avoid gripping the polished piston rod with pliers, a vise, or pincers. Even a small scratch can damage the seal as the piston moves. Also avoid painting, heating, puncturing, or attempting to refill the strut. Gas springs are sealed, pressurized components that should be replaced, not repaired.

If the tailgate still sags after the struts have been replaced correctly, check for play in the hinges, latch alignment, body damage, and additional equipment. A heavy aftermarket spoiler, extra soundproofing, or rear-mounted equipment may exceed the struts’ factory specifications. W this situation, don’t simply install the strongest strut available - account for the extra weight and use a suitably designed solution.

A properly matched pair of tailgate struts is a small repair with a huge impact on everyday use. Match the OEM reference number, support the tailgate before removal, and make sure every clip is locked in place. The extra minute spent checking is cheaper than ordering a second pair or repairing a damaged tailgate.