Anti-roll bar link for your car

The stabilizer coupling rod or suspension link is a relatively inconspicuous component with an important function. It transmits the swinging forces of the bodywork to the stabiliser. Its aim however is not compensating these forces (the suspension's task) but linking the bodywork movements via the wishbones to the suspension. A defective coupling rod would cause a considerable loss of driving comfort, causing the car to "swim". Ignoring this, you risk serious accidents as evasive manoeuvres in a dangerous situation would hardly be possible.

Where is the coupling rod located?

• The vertically placed stabilizer coupling rod can be found right behind the front wheels when they are fully turned. Depending on manufacturer they are either installed on the front axle only, or on both axles, although never only on the rear axle. In this position they are less accessible as the rear wheels cannot be steered, additionally complicating the installation.

How does the coupling rod function?

• The most important elements of the coupling rod are its connections. As bolt connections, forked connections or indirectly through rubber bearings or a ball joint they largely define the force transmission.
• On one end the bar is connected with the chassis (vehicle body) and at the other end with the stabiliser. Upward or downward motion of the chassis is adequately transmitted.

What happens in case of a defect?

• A typical sign of a coupling rod defect is a knocking sound in the foot well directly above the wheels.
• Gradually the driving quality deteriorates. Initially only slightly, but gradually the car will swing more intensively, which is particularly felt in road curves making steerage compensation necessary.
• When the coupling rod is broken, driving safety is compromised and avoiding dangerous situations is more difficult due to an impaired driving quality.

Possible causes:

• The coupling rod absorbs high pulling and pushing forces and is constantly strained during driving. Material fatigue due to stress is its main enemy and the most common cause of a defect.
• Additionally, the connections lose their effect as a result of strain and ageing. Screw threads can get damaged, rubber bearings become porous, ball joints start to grind.

To the garage or DIY replacement?

• In many cars, DIY replacement of the coupling rod is possible without any problem. No special tools are necessary and as it can be installed in only one possible direction; there is not a lot that can go wrong. Depending on manufacturer, a specific torque might apply of which you need to be aware.

Tips for replacement:

• At the front, the coupling rods are only adequately accessible when the wheels are turned. For the rear axle, the car must be hoisted and the wheels removed.
• The most important challenge is eliminating the load, requiring support of the wishbone by a lever. Only then it is possible to unscrew both connections or lever them off with a crowbar.
• The application of lubricant, milk fat or vaseline on rubber bearings and stabilizer bushing can simplify their assembly.

What to do in case of defective rubber bearings

Often the rubber bearings of the coupling rod, functioning as a kind of damper, become porous, crack and no longer function properly. Their separate replacement is not simple and in most cases not recommended either as the tiny cracks in these parts are often invisible, even for professionals. Most manufacturers include rubber bearings or other connecting parts in the coupling rod kit. Furthermore, they have to be replaced for the entire axle to prevent wear on one side.

What costs can be expected

As long as you refrain from constantly taking your driving to the limit, you don't need to worry about the strain for the coupling rods. Generally, age affects them most. After approximately 200.000 driven kilometres a regular sight check should be performed. Ultimately at 300.000 km it is generally the end. A set of coupling rods costs between 15 and 50 euro (c. £13 – 44), the more expensive products promising a better driving comfort during the entire life span. Even apparently cheap spare parts such as coupling rods offer another saving opportunity. When visiting our shop, where we not only offer daily discounts but also special budget actions on our already modest prices, you can save a considerable amount of money.