Wind deflector

Wind deflectors and A-pillars help determine airflow, water drainage, visibility and structural integrity around the windscreen and doors. On MAN and Mercedes trucks, buses and vans, these are vehicle-specific body parts with different contours, mounting points and seals. A wind deflector or A-pillar must therefore always be identified using the vehicle chassis number. Visual comparison or selection based solely on the model name is never sufficient, even when, for example, a MAN TGL, TGS, TGX or TGE, or a Mercedes Atego, Actros, Arocs, Sprinter or Vito appears visually similar.

Wind deflectors are generally made from impact-resistant plastic, such as ABS (Acrylonitrile Butadiene Styrene), ASA (Acrylonitrile Styrene Acrylate) or fibre-reinforced composite. They reduce wind noise, direct rainwater away from side windows and mirrors, and protect the window area against road spray. Depending on the version, they are fitted using clips, plastic rivets, bolted connections or double-sided bodywork tape. The fit must be fully flush: a gap causes whistling noises, dirt accumulation and local paint wear due to vibration.

The A-pillar is the load-bearing cab pillar between the windscreen and front door. On trucks, this pillar forms part of the cab structure and carries loads from the roof, windscreen frame and door frame. On buses, such as the MAN Lion’s City, Mercedes Citaro, Neoplan Tourliner or Skyliner, A-pillar trims may also incorporate provisions for exterior mirrors, cameras, indicators or cable pass-throughs. Always distinguish between left- and right-hand sides, cab height, mirror version, windscreen variant and any preparation for camera or driver assistance systems.

Typical damage results from branches, car wash contact, mirror incidents, stone impact and manoeuvring damage. On plastic wind deflectors, hairline cracks around mounting holes, broken clips, warping due to UV ageing and detached tape are common. First check whether the part is fitted under tension: use a feeler gauge to measure the gap between the deflector and the cab bodywork at several points. An uneven joint or local opening indicates deformation, incorrect clips or a damaged mounting surface.

A dented or bent A-pillar requires more than a cosmetic assessment. Remove the trim and inspect the bodywork for cracks in the paint layers, corrosion around weld seams, detached sealant seams and deviations in the windscreen frame. Measure the diagonals between fixed reference points on the left and right; differing measurements may indicate cab damage after a collision. Also inspect the door shut line, window seal and windscreen adhesive bead for leaks. Water traces behind the A-pillar trim or corrosion on electrical connectors require the seal to be repaired before fitting a new trim part.

Replace wind deflectors when cracks extend to a mounting hole, the material is permanently deformed or mounting tabs are missing. Do not reuse expanded clips, corroded screws or hardened sealing material; these will quickly cause rattles and detachment again. Clean the mounting surface with a suitable degreaser and remove old tape completely without damaging the paint layer. For tape bonds, use only the specified tape and primer combination, and observe the application temperature and curing time.

For a structurally deformed A-pillar, straightening or welding is only appropriate in accordance with the body repair guidelines of the manufacturer. A visible trim panel must never conceal structural damage. After installation, check the free movement of the door and window, the operation of mirrors or cameras, and carry out a targeted water test along the windscreen, roof edge and A-pillar. Correctly fitting body parts and, where necessary, colour-matched supply help keep downtime following cab damage to a minimum.