Longeron: replacement and selection

When and why it is necessary to replace longeron

Operational lifetime of the longeron is not specified. Replacement of the part is performed at appearance of cracks, deformation and corrosion.

Mechanical damages of the longerons are usually the result of frequent operation of the vehicle on rough roads or heavy impact in a road accident. Corrosion appears on the components due to influence of moisture.

Signs of longerons defectiveness is excessive or uneven wear-out of tyres, nonremovable disbalance of wheel alignment angles. Worsening of road-holding ability of the car at straightforward movement may also indicate longerons defectiveness.

Improper replacement of these components may cause violation of the body geometry: all the parts, mounted to longerons will be installed with offset. That is why the procedure should be performed at a service station. Geometry of a damaged longeron, usually, is restored with the help of special bodyworks equipment before demounting. After replacement of the component, wheels alignment angles should be checked and adjusted if necessary.

How to select longeron

The longerons are divided by construction into two types: solid and composite. The first ones are solid parts, while the second consist of a few elements. Advantage of the composite longerons lies in the fact, that if defect was found, you can replace only a damaged element, not the whole construction. In their turn, the solid components are able to withstand higher load.

Two longerons are installed on most car models: the left and the right. Each of them may be divided into the front, middle and rear. Most components are made of sheet steel.

As the longeron is a main load-carrying member of car construction, you should thoroughly think over choosing of this detail. High-quality wear-resistant longerons are made under such brands as Van Wezel, Diederichs, Blic, JP Group and others.

During selection of the part you should be guided by its mounting location: the front or rear car part, on the right or left. Moreover, the longerons vary from one another by shapes and dimensions, according to which car they are designed. Consider the brand, model, body type and manufacturing year of the car, during purchase of the components.