Mudguards

Rear mudguards limit the spread of water, mud, stone chips and loose material from driven and non-driven rear axles. They protect not only traffic behind the vehicle, but also brake lines, air springs, EBS sensors (Electronic Braking System), wheel brakes, chassis wiring and underbody components. On MAN and Mercedes trucks and vans, a mudguard must therefore provide sufficient coverage over the tyre width and wheel circumference without coming into contact with the tyre during full suspension compression or axle articulation. Always identify each mudguard, including supports, mounting brackets and mud flaps, by chassis number. Visual comparison or selection based solely on the model name is never sufficient.

Mudguards vary according to axle configuration, tyre size, chassis layout, wheelbase, air suspension, twin-wheel configuration and the position of fuel tanks, battery boxes or body mounting brackets. For example, a mudguard for a MAN TGL, TGM, TGS, TGX or TG3 has different radius dimensions, mounting points and cut-outs than a version for a Mercedes Atego, Axor, Actros, Arocs or Econic. For MAN TGE and Mercedes Sprinter, Vito and Vario models, the body variant, rear-wheel drive and flatbed or panel van body configuration also determine the correct wheel protection.

On rear axles, mudguards are often mounted on supports or integrated into side panels or wheel arch modules. Dimensional stability, alignment with bodywork and clearance for the air suspension are crucial here. Common materials include impact-resistant polypropylene (PP), polyethylene (PE), glass-reinforced plastic (GRP) and, for heavy-duty construction site or tipper applications, steel or aluminium. Plastic variants are corrosion-resistant and flexible; metal mudguards offer greater local rigidity but require an intact coating to prevent corrosion.

There are one-piece mudguards and mudguards made up of three sections: a section in front of the wheel, a section behind the wheel and an upper section. The upper section is also referred to in Dutch as the bovendek. When a three-piece mudguard is fitted to the rear axle, the section behind the wheel often serves as a support for rear lights and number plates. On a truck with tandem axles, there is also a one-piece mudguard mounted over both axles.

Typical damage is caused by reversing into loading bays, tyre contact due to overloading, stone chips, compacted dirt and damage to supports during off-road work. First check whether the mudguard has cracks around bolt holes, strap holders, brackets and transition radii. White stress marks in black plastic often indicate material fatigue, even when the panel has not yet fully cracked. On metal versions, assess corrosion, peeling paint, bent edge profiles and hairline cracks near welded joints.

Park the vehicle on a level surface and inspect the tyre-to-mudguard clearance on both the left and right sides. Measure the clearance at several points with the vehicle loaded or with the air suspension at ride height. Then check at maximum suspension compression that the mudguard cannot contact the tyre, tread edge, twin tyre or snow chain area. Uneven clearance may indicate a bent mudguard support, displaced chassis bracket, worn air springs or damaged axle guidance. Also check the tightening torque and fit of the mounting bolts; overtightened bolts without spacer rings cause stress cracks in plastic parts.

Replace mudguards when cracks extend into the mounting areas, when the original shape can no longer be restored or when tyre contact is visible. Welding or bonding severely deformed plastic parts is often only temporarily reliable under intensive use, especially on vehicles operating with high axle loads, varying payloads or frequent off-road use. Also replace damaged brackets, vibration dampers, mounting clips and mud flaps at the same time; a new panel fitted to a bent support will crack again.

Before installation, clean the chassis mounting points and treat corrosion on steel supports. Use only mounting materials with the specified diameter, strength class and washers to avoid point loads. Correct fitment reduces vibrations and prevents dirt from accumulating around rear axles and brake components. Braem can assist with parts checked by chassis number and, where necessary, matching body components for an efficient repair.