How to choose a trunk shock absorber for a car?

Gas-filled hood struts wear out over time. Weaker parts tend to fail in cold weather because gas pressure drops in low temperature conditions. In hot weather, such racks will work fine, but it is still better to replace them.

When purchasing new parts, keep in mind that the thrust struts for the trunk and hood lids may differ in length and types of fastening. Some have a hinged connection at the ends; there are models with a combined fastening, combining hinges and a rigid fastening with a permanent loop. There are products with a flattened support at the end of the rod, connected to a fixed mounting pin.

It is necessary to measure the length of the stops on the car in the extended position and buy a new part with the same dimensions. It would be even better to take the old stop with you to the store.

Prices for branded, high-quality shock absorbers (supports) for the hood or trunk of a foreign car in online stores vary between 2500–2800 rubles per pair. For domestic cars VAZ, Lada, etc. their cost can start from 300 rubles per piece.

After purchasing new suitable parts, you can begin replacing the stop. The following instructions will help you complete it.

Replacing stops - step-by-step instructions

Open the trunk and support its lid with some strong wooden beam. It is advisable to replace both stops with bars so that it is convenient to work with them from either side.

After installing the safety stops, parts are replaced. It is quite simple and takes no more than 10 minutes. The hinged ends are secured with some kind of clamp. Typically, either a flat clamp or a C-shaped clamp is used. The latter should slide through the bottom of the cracker, and then under the ball. Only in this case will the fastening be reliable.

It is important to push out the old shock absorber correctly. Some car enthusiasts do this by using a screwdriver, inserting it between the ball joint and the metal, and then pulling like a lever. For this purpose, it is better to use needle-nose pliers or a small screwdriver, with which you should carefully lift the clamp from the cracker. Then all that remains is to pull the cracker off the ball. The same manipulations should be repeated with the second end of the stop.

Installing the new part will be made easier by applying a small amount of silicone grease to the inside of the cracker. To do this, the clamps are installed in a half-open position. Then you need to pull a new cracker onto the ball and snap the clamp.

It also happens that the hinge joint does not have a clamp, and the ball joint is screwed to the body panel. In this case, it is recommended to use a hex wrench to remove the old ball joint. You can screw on the new heel using an open-end wrench.

If the stop is mounted on a rigid mount, you just need to unscrew the bolt holding it in place.

The fastening on the pin should be disassembled using a locking spring washer or pin to prevent the stop from slipping off the pin. To release the lock washer, it must either be pushed or pulled in a specific direction. In some cases, it is enough to push it slightly with the tip of a screwdriver. You can also grab the end of the washer with needle nose pliers and pull it out. After this, the old hood or trunk lid stop must be removed, a new one installed, and the lock washer smoothly returned to its place until it snaps into place.

Usually the piston column has a coating that is resistant to external influences. However, when working, you still need to act carefully so as not to damage it. It is also important to install the new part correctly. If the old stop was with the piston down, the new one should have the same position. A device containing nitrogen or hydraulic fluid will operate more smoothly if the rod end is pointed down.

After installing the new shock absorbers, you can remove the wooden block holding the hood or trunk and enjoy the convenience of the system.

Watch a video about replacing trunk shock absorbers on a Nissan March K12:

Step-by-step instructions for replacing the trunk lid shock absorber
Types of shock absorbers
By type of depreciation
According to the working substance of the shock absorber
What to look for when choosing a shock absorber
How to replace a shock absorber yourself
Replacement Tool Set
Step-by-step instruction

Something important

It would not be superfluous to note that there is a choice in terms of the working substance. In principle, there are no differences from the shock-absorbing strut of the car chassis; there are three types:

Gas - extremely reliable and durable. Not afraid of sudden temperature changes.
Gas-oil - less reliable, but more economical. This type of shock absorbers quickly fails with regular temperature changes.
Oil is the most common and versatile option. In terms of its performance characteristics, it is something between a gas and gas-oil shock absorber. Service life with proper care is 5-6 years.

From all of the above, we can conclude that the best option would be a dynamic gas shock absorber for the hood or trunk. It will work smoothly and for a long time. Hydraulic struts should not be ruled out. True, it is quite difficult to say about their service life. They may leak after a year of use, or they may last up to 10 years.

Purpose of the trunk lid shock absorber

The trunk lid and hood of a car can cause a lot of trouble for the car owner - they can treacherously close and cause injury, which has long been the subject of jokes and the basis of comical situations in movies. Things are even worse with the trunk - it can be inconvenient to open it with luggage in your hand or just after a trip on dirty roads. Therefore, for a long time, automakers have been looking for a solution that would make using the trunk and working in the engine compartment more comfortable. One of these solutions was special devices - gas springs or stops.

The trunk gas strut, or trunk lid shock absorber, is a whole group of pneumatic and hydropneumatic mechanisms that solve several main problems:

— Automatic lifting of the trunk lid; — Smooth lifting and lowering of the trunk lid; — Holding the trunk lid in the raised position without using additional stops; — Prevention of impacts of the cover when reaching extreme points (when opening and closing).

Thus, shock absorbers make using the trunk more convenient; they prevent intense wear of mechanisms, deformation of the lid and body parts, and destruction of sealing elements.

Automakers began to widely use trunk lid shock absorbers about twenty years ago, and they were also installed on domestic cars (VAZ, Volga and others). Today, there are practically no passenger cars produced without trunk shock absorbers, and there are a large number of types and varieties of shock absorbers themselves.

Choice

The choice of shock absorber must be made taking into account several factors. For example, the first step an owner must determine is how often they will use the rear door or cargo area.

In addition, you will also have to take into account the climatic features of a certain region, as well as compliance with the requirements of the automaker.

Finally, the weight of the cargo area or hood should not be neglected. The heavier the body parts, the greater the buoyancy force you need to select a shock absorber.

Types, design and principle of operation of shock absorbers

The most widely used trunk shock absorbers are of two designs:

— Pneumatic (gas); — Hydropneumatic (by analogy with suspension shock absorbers, they are often called gas-oil shock absorbers).

Pneumatic shock absorbers are more correctly called gas springs or gas struts. In these devices, the force on the rod and damping properties are created by the gas contained under pressure. Gas springs are widely used due to their simplicity of design and reasonable price.

Structurally, a gas spring is a cylinder, inside of which there is a piston on a rod. The rod outlet is closed by a stuffing box, which ensures the tightness of the cylinder and lubrication of the rod. The internal space of the cylinder is filled with gas under pressure of several atmospheres, usually nitrogen is used as the working substance. The shock absorber also provides for the possibility of gas flowing between the cylinder cavities separated by the piston. These can be either bypass valves in the piston, or channels in the cylinder walls that the piston crosses at a certain point in its path. Many shock absorbers of this type also have a closed cavity containing oil, which is used only to lubricate the piston rod.

Hydropneumatic trunk shock absorbers (which, by the way, are also called gas springs) differ from gas ones in that their cylinder contains a certain amount of oil. The oil layer is located in the lower part of the cylinder (at the rod exit) and is only necessary for damping (shock absorption) when the trunk lid is fully opened.

Popular shock absorber models

As you know, today products from several manufacturers are entering the market. Let's take a closer look at the models and find out their strengths and weaknesses.

DELLO from Germany

DELLO is a manufacturer of various spare parts for Volkswagen, Audi and other European cars. It is a brand from the first letter in Hamburg, as well as throughout Germany. The products, including shock absorbers for the cargo compartment and hood, are very popular in Russia.

It will be useful to know that some of the DELLO assortment is produced by third-party companies, but under a patent. Such products are sold under the AutoMega brand.

Spare parts from this German company are unrivaled, but sometimes unflattering reviews are heard. According to experts, if you take into account the cost of products, DELLO shock absorbers are a very profitable option with good quality. On the other hand, to be completely honest, the quality of the products somehow reaches 3 on a 5-point system.

MONROE

A very well-known manufacturing company in Russia. The design of Monroe products is always based on special technology. It is always head and shoulders above its competitors.

It will be interesting to characterize one of the manufacturer’s models:

The buoyant force of the model from Monroe ML5809 is 410N.
The internal working component is gas.
The length of the cylinder is 19 mm.
Product length – 536 mm.

The cost of this model rarely exceeds 700-800 rubles, although in some areas of the country they can be more expensive.

In general, if you ask the users of Monroe products themselves, they will call the price of shock absorbers quite affordable. But the most important thing that attracts people from Monroe products is the ability to modernize them. For example, if you need to repaint the fasteners so that they do not glow with the shine of chrome or for other reasons, this can be easily done.

After replacing the old stops with new ones from Monroe, 75 percent of car owners notice that when the lid is opened to a third of the height, almost no further effort is needed, since it is picked up automatically.

Nakayama

A Japanese manufacturer that produces products at very low prices. Shock absorbers for the lid from Nakayama at one time could even be bought for 100 rubles.

Issues of operation, maintenance and repair of the shock absorber

Modern trunk lid shock absorbers are very reliable and durable, designed to last thousands of cycles under the most severe conditions. However, to extend their service life, you should follow a few simple recommendations. For example, in the winter season you should open the trunk without jerking, preferably by helping the lid to lift up. Also, do not jerk the trunk lid to the top point, as this leads to an excessive increase in pressure in the gas spring and to its wear. Finally, shock absorbers should not be subjected to impacts, it is not recommended to disassemble them (since there is high pressure gas inside), etc.

The trunk lid shock absorbers do not require special maintenance or repair. When the service life is exhausted or in the event of a malfunction, this device is replaced with a new one.

When purchasing new shock absorbers, you should choose those models recommended by the car manufacturer. Of course, replacements are possible, but you should not replace shock absorbers with dynamic damping with shock absorbers with hydraulic damping. In this case, the load on the trunk lid and body parts will change, and installation problems may arise.

It is better to replace shock absorbers in pairs. When replacing, you should follow the method of installing the shock absorber - with the rod down or with the rod up, depending on its type (as mentioned above). The procedure for removing and installing gas springs is indicated in the maintenance and repair instructions for this particular car; this work usually does not require special qualifications (but it is better to entrust it to specialists if the car is under warranty).

What types of shock absorbers are there?

Shock absorbers, like most other car parts, can be divided into subtypes. They are:

Gas;
Oily;
Gas-oil.

Each type has its own advantages and, of course, disadvantages, which can be minor or, conversely, unpleasant in some situations.

Gas shock absorbers

Gas shock absorbers are the lightest, since the weight of the entire part is almost equal to the weight of the body. On some sports cars, a few grams removed from the total weight of the car often pleases its owner, but in practice this is practically unsuitable. The main advantage of gas shock absorbers is their durability. Most likely, with proper use, they will last the entire life of the car without any problems. This is the most resistant type of spare parts to weather conditions, dirt and improper care. It operates more gently, and the gas does not freeze, so such a shock absorber can be used without problems even in the most severe climatic zones. But such pleasure costs much more than all other types. The rival company can boast of good devices - high-quality shock absorbers at an affordable price. Gas shock absorbers are most suitable for the tailgate as they can withstand heavy loads.

Gas-oil mechanism

Hood shock absorber
Gas-oil shock absorbers also have acceptable characteristics. They differ from the previous type in their filling; a gas-oil mixture is used as a shock-absorbing liquid. In terms of its parameters, it is worse than clean air, but nevertheless, such shock absorbers cannot be called completely bad. The hood lid equipped with them will last a long time and will open without problems in almost any weather. When choosing a gas-oil mechanism, it is necessary to take into account the weather conditions in which it will be operated.

Oil shock absorbers

The cheapest type of shock absorbers. They are installed on inexpensive cars that are not designed for a long service life. They are less reliable and fail faster than others. These spare parts are very capricious in various weather conditions. At very high temperatures, their effectiveness decreases due to heating of the oil, and in cold weather you have to handle such shock absorbers very carefully.

When the oil freezes in them, the movement of the rod becomes more difficult and it can simply be bent with a sharp jerk, especially if it is made of low-quality metal. These spare parts are very cheap, therefore, even if you take into account the fact that they will not last long, you will not incur large expenses.

It is up to the car owner to decide which mechanism to install on his car. A completely acceptable combined option, for example, you can install gas systems for the hood, and select a rear door shock absorber from a range of gas-oil systems. So, you will not only be able to save on a second pair of gas mechanisms, but also to a greater extent adapt a specific type of mechanism for your body element.

Rival produces some pretty good shock absorbers. Gas mechanisms from this company have an excellent appearance, a long service life and a relatively low cost. Many auto repair shops work with the products of this particular company.

A very popular line of shock absorbers is rival comfort. They are suitable for many cars with standard opening angles of the hood, rear door, and trunk. They have an operating temperature range from -40 to +80°C, are treated with anti-corrosion agents, and also have a stylish and modern color. A nice addition to the rival products is the slowdown at the end of the opening and the closing effect (after a certain point, for example, the hood shock absorber itself pulls the lid until it is completely closed).

Hood shock absorber, why you need to choose a shock absorber with a long stroke

When choosing a shock absorber for the hood, you should carefully consider the opening length. It’s not uncommon for drivers to choose shock absorbers that are too short, resulting in the hood not opening completely. Thus, the car owner cannot check the oil level because the dipstick does not come out all the way. This also applies to the trunk of a car. If it doesn't open high enough, you can forget about large loads, since they won't fit into the trunk of your car. In addition, if a service station worker (and perhaps you yourself) needs free access to all the insides of a vehicle’s engine, you will hear everything that the mechanic is thinking about you. This is why you should choose a hood shock absorber with a long stroke.

Conclusion

Most consumer reviews indicate that trunk shock absorbers are a convenient and practical thing. They significantly increase the level of comfort when using the luggage compartment of a car.
You can purchase stops for free sale on the Internet or car dealerships. There are several Russian and foreign manufacturers that offer good quality at an affordable price.
The stops are installed in the standard mounts. Any driver can equip a car with these parts. The whole procedure takes no more than half an hour.

We reanimate the torsion bars of the VAZ-2115

We won’t discuss the car’s designers and guess what they were guided by when they decided to adapt such unreliable devices to support the massive trunk lid of the VAZ-2115. It’s better to talk about how to find a way out of this situation.

As is customary in any civilized society, a car enthusiast, having discovered a malfunction, will, of course, try to find the right part in a car shop. But in this case, failure awaits him in advance: it is very difficult to find torsion bars on sale, and if there are no familiar craftsmen from a car service center, then you can bury the idea of making them. If a miracle happens, and the necessary copies are found on sale, then there is no chance at all of installing them on the VAZ-2115 without the help of a specialist. It is necessary to remove the rear seat, dismantle the shelf, take measures to ensure that the trunk lid is open during the entire installation process... In general, if you like to overcome obstacles, this is your finest hour!

DIY parts repair

Craftsmen with experience working with metal have found their own solution, which is effective, but completely unacceptable for those who are only used to riding. The point is this: the torsion bars used in the trunk of the VAZ-2115 have a twist of only half a turn around their own axis. If you tighten them one more turn, the problem will be solved. The only question is, do you know how to create sufficient force with the help of improvised means to carry out such an operation? That's it...

A more accessible way is to adapt the clutch springs by attaching one end to metal plates installed with self-tapping screws on the trunk lining, and the other to the lid. This, of course, is a more suitable plan, but it also has its own unpleasant moment. Firstly, the skin is not a very reliable basis, and it is better to attach the strip to the body. Here, too, you need to act skillfully so as not to drill unnecessary holes. Secondly, the springs are still not suitable for working with the trunk lid of the VAZ-2115 and have the unpleasant property of stretching. Of course, these are not torsion bars, and replacing them will not be so difficult, but it is unlikely that any car owner wants to rack his brains and spend money once again.

Self-installation of trunk gas struts

Equipping the Lada Vesta with gas stops is a simple operation, since they are attached to specially provided standard places. Installation requires only two keys for 10, two keys for 13 and half an hour of time. All necessary fasteners: bolts, nuts and brackets are supplied with the parts.

Let's look at the process of installing trunk lid shock absorbers step by step:

We screw the lower brackets to the right and left hinges of the trunk. They have special holes for this, so you don't have to drill anything. To tighten the nuts, use two 10mm wrenches.

The upper brackets must be secured to specially provided platforms from the inside of the lid. They are attached to the studs using the nuts included in the kit.

The next step is to install ball heads on the lower brackets, where the shock absorbers themselves will be inserted. To do this you need to use two keys

Since the fastening bolt is short enough, the nut can be lubricated with a thread locker so that it does not unscrew during operation.

Install the ball head on the upper brackets. It is placed in the hole with the ball inward. For reliability, the nut must also be coated with thread locker or sealant.

After all the brackets and fastenings are installed, we proceed to the installation of the gas stop itself. Before installation, the part must be pumped by squeezing it several times in the vertical direction, resting it on the floor. The shock absorber simply snaps onto the already installed ball bolts. The installation of the right and left stops is similar.

When installing shock absorbers for the trunk lid of the Lada Vesta, one nuance should be taken into account. On the left loop, the corrugation with wiring will touch the shock absorber, which should not be allowed. To avoid unwanted contact, the corrugation must be removed from the standard fastening, placed behind the loop and secured in several places with plastic ties.