Tailgate dampers: function, defects and replacement

Tailgate dampers not only increase comfort when using the trunk. These components also ensure that your trunk lid behaves as expected. In this way, it is kept open and does not close again by itself. The gas pressure dampers thus ensure a lower risk of injury. In this article we explain how these vehicle parts work in principle and how and what defects can occur. In addition, we will take you by the hand and provide you with a procedure for changing the tailgate dampers. So you can easily carry out such an exchange yourself and thus save time and money.

The structure of tailgate dampers

Tailgate shock absorbers are special components which are also referred to as so-called gas pressure springs. The core element of these components is a gas under high pressure, which provides the desired spring force. This is where the term pneumatic spring comes from. While classic, mostly metallic coil springs provide a different force depending on the degree of compression, this is almost independent of the spring travel in the case of gas pressure springs for the trunk. In addition, it is a particularly compact design. The main components, in addition to the gas under high pressure; mostly nitrogen; are a closed piston and a so-called pressure tube. In addition, there are different seals and guides for the piston, and with other gas pressure springs there is also a second damping piston.

The function of tailgate dampers

If you close your trunk lid, this will move the trunk shock absorbers, which are often present on both sides. Pushing the piston into the tightly closed cylinder compresses the filling gas and thus builds up a higher pressure. This creates a counter-pressure, which you will usually also notice by the fact that the speed of the tailgate decreases as it closes. The forces are transmitted by so-called ball head couplings, with which the gas pressure springs are equipped at both ends. If you now start to open the trunk lid again, you will be supported by the original counter-pressure that the trunk dampers generate when closing. This also makes it much easier for you to move the trunk lid, which is often very heavy, in a controlled manner. When fully extended, the dampers for the tailgate keep it in the open position.

What happens if the trunk gas struts are defective?

The failure of your tailgate dampers can be announced insidiously or they suddenly stop working. There are two symptoms that can be assigned to these components. This includes the sluggishness of the trunk lid when opening, but also that the luggage lid is not held securely in the open position.

As a rule, however, such symptoms appear gradually and more and more frequently. However, there are also repeated reports of this type of component failing spontaneously and completely. The latter is probably mainly due to leaks in the piston area or to seals that have failed completely. If the tailgate dampers are largely made of metal, as is often the case with particularly old vehicle models, rusting through can also cause very similar symptoms. It is also important to know that usually one damper fails first (there are usually two) and the other can still at least partially fulfill the function. Nevertheless, when repairing the tailgate struts, you need to make a bilateral replacement to prevent deformation and imbalance.

Install new tailgate dampers yourself

Repairing tailgate dampers is not difficult. But first of all you have to get the right spare parts. In addition to the correct fasteners, these must also meet the other desired parameters. Of course, this includes the dimensions, but also the spring forces achieved. This is the only way to ensure that your trunk lid behaves as desired.

When repairing the tailgate damper, it is very very important that you make sure that it cannot fall down during installation and removal. So the first step is to open your trunk and secure the tailgate. A sufficiently long support is suitable for this, which you should also position in such a way that you do not accidentally knock it off when handling it. An alternative possibility is to have someone else hold the trunk open.

Before loosening the dampers, it is important to note that you should try to replace the most affected one first, as this will reduce the risk of sudden closure should the post and/or aids fail. As already described, the tailgate shock absorbers are attached using ball-joints. These are constructed in a similar way to a classic trailer hitch on cars. In many cases, this connection is secured by a clasp or a so-called retaining clip. Of course, you have to remove these first for disassembly. To do this, use a screwdriver to lift the fastener slightly and then grab it. Then you can usually simply pull it off. Avoid damaging your paintwork by handling the screwdriver. Be sure to keep the retaining clip in a safe place if the new replacement parts do not come with new fasteners. Now the shell of the ball joint can simply be pulled off the ball. Repeat this process at the other end of the gas spring and then remove it. After a short cleaning of the ball heads, you are ready to install the spare parts. In most cases, the new ball joint also has a new fastening clip, which often does not have to be removed at all. You can almost always press the new shell directly onto the ball head.

Conclusion

Components that are intended to provide comfort in particular can also fail. In addition to convenience, safety also plays an important role with the tailgate gas springs. Because replacing or installing new tailgate dampers is not particularly difficult, you should not shy away from it either. The most important thing is that the tailgate is safely supported by tools or colleagues.

A tip from CarTipsandmore: As with many other repairs, it can quickly pay off to lend a hand, since you this can save a lot of money. In this case in particular, effort is fortunately kept within limits. In certain circumstances, it may also be worth considering installing reinforced gas springs. This makes opening easier and the flap also holds better in the open position. Unfortunately, one disadvantage is that you have to use more force to close the trunk lid again.