Upholstery

Side trim panels form the finishing and protective outer layer of the cyclist protection system or side guard between the axles of trucks. These panels protect chassis components, air tanks, AdBlue tanks, fuel tanks, battery boxes, wiring harnesses and compressed-air lines against stone impact, spray water and contact damage. At the same time, they reduce the risk of cyclists or pedestrians ending up underneath the vehicle in the event of a side collision. On MAN TGL, TGM, TGA, TGS, TGX and TG3, as well as Mercedes Atego, Axor, Antos, Actros, Arocs and Econic models, side trim panels vary according to wheelbase, chassis configuration, tank layout, exhaust configuration and mounting points. Specific side panels or guards may also be fitted to MAN TGE and Mercedes Sprinter vans. Parts must therefore always be identified using the vehicle chassis number; visual comparison or selection based solely on the model name is never sufficient.

Depending on the application, side trim panels are made from impact-resistant PP (polypropylene), ABS (acrylonitrile butadiene styrene), glass-fibre-reinforced composite or aluminium sheet material. Plastic panels are lightweight and corrosion-resistant, but may become more brittle on impact at low temperatures. Aluminium versions retain their shape better, but are susceptible to dents, cracking around mounting holes and galvanic corrosion when in contact with steel brackets without an insulating layer.

A complete cyclist protection system generally comprises longitudinal profiles, vertical brackets, connecting brackets, cover panels, end caps and mounting hardware. The side trim panel itself is therefore not always load-bearing, but it must fit correctly onto the supporting structure. Pay attention to the length between the axles, clearance around the tyres at full suspension travel, the position of step boxes and accessibility of service points. On vehicles with air suspension, sufficient clearance must also remain at the lowest ride height and during chassis articulation. Incorrect panels or unsuitable brackets can rattle, chafe against lines or interrupt the legally required guard.

In practice, damage is mainly caused by contact with loading docks, posts, kerbs, snow build-up, construction sites and manoeuvring in confined distribution areas. Common faults include cracked plastic around clips or bolt holes, loosened mountings due to vibration, deformed aluminium panels, missing end caps and worn mounting holes. A loose panel not only causes noise, but can tear further in the airflow and pose a danger to other road users.

First clean the entire side guard so that hairline cracks, corrosion and deformation become visible. Then check the brackets and longitudinal supports for misalignment using a straightedge or laser alignment. Measure the distance from the panel to the tyre, chassis and adjacent components at several points; assess the vehicle at normal ride height and, where possible, with the air suspension fully raised and lowered. Check bolted connections for missing locknuts, damaged threads and oval holes. Also inspect the wiring harnesses, compressed-air lines and tanks behind the trim panel for chafing marks or impact damage.

Replace side trim panels when cracks extend from a mounting point, when the material is permanently deformed or when the panel no longer fits the original mountings without stress. Repairs using plastic welding are only appropriate for limited, non-load-bearing damage and where the original rigidity is retained. A panel with torn mounting areas or missing sections must be replaced, together with damaged clips, rubbers, brackets or spacer bushes.

Install the trim panel without pre-tension and use corrosion-resistant fasteners of the specified size and tightening torque. Fit insulating washers where aluminium and steel come into contact. Correct fitment reduces wind noise, prevents components from working loose and keeps vulnerable chassis installations reliably protected. For a fast repair, Braem can technically match side trim panels and associated mounting components to the exact vehicle configuration.