The door lower trim panel is an essential interior component that protects the door structure and enhances cabin aesthetics. A complete door lower trim panel set includes inner and outer covers, rubber buffers, and all necessary fasteners. This genuine HOWO door lower trim panel kit contains left and right lower trims, strips, inner panels, rubber blocks, and a full set of bolts, washers, screws, and spring nuts. When you choose authentic Howo Parts, you receive a complete door lower trim panel assembly engineered specifically for the HOWO MAX 4X2 cab doors.
The hexagon bolt with flange (ZQ1840612F31) is a class 8.8 fastener used to secure various door lower trim panel components to the inner door structure. Six bolts are supplied, each with an integrated flange that distributes clamping pressure and eliminates the need for a separate washer. The bolts have a M6 thread pitch of 1.0mm and a length of 12mm, making them ideal for attaching plastic trim panels without damaging the material. The flange has a serrated underside that bites into the panel, preventing loosening from door slam vibration.
The lower trim panel strip of right door is a narrow plastic molding that covers the bottom edge of the right front door. This strip protects the door skin from scuffs and hides the mounting holes for the main trim panel. The strip is made from UV stabilized ABS plastic with a textured matte finish that matches the original interior. It includes integrated clips that snap into the door sheet metal, and the hexagon bolts with flange are used at the ends for additional retention.
The lower inner trim panel of left door is the main decorative panel that covers the inner structure of the left front door below the armrest. This panel is injection molded from high impact polypropylene and features a fabric or vinyl surface that matches the cab upholstery. It includes cutouts for the door speaker, storage pocket, and wiring harness access. The door lower trim panel uses multiple fasteners including hexagon flange bolts and tapping screws to ensure a rattle‑free fit.
The outer lower trim panel of right door is a decorative cover that attaches to the exterior side of the right door at the bottom. This panel protects the door edge from road debris and provides a finished appearance. It is made from weather‑resistant thermoplastic and is secured with the supplied hexagon bolts and large washers. The panel has a subtle ribbed texture that matches the exterior styling of the HOWO MAX 4X2.
The outer lower trim panel of left door is the mirror image of the right side, providing identical protection and styling for the left door. This door lower trim panel component is precision molded to follow the contours of the left door sheet metal. It is finished with a black powder‑like coating that resists chipping and UV fading. Installation requires the use of hexagon flange bolts and the large washers to spread clamping load.
The inner panel of right door lower decorative panel is a secondary trim piece that fits behind the main lower trim, adding rigidity and sound deadening. This panel is made from compression molded fiberboard with a foam backing that absorbs road noise. It sits between the door steel and the outer decorative cover, reducing vibration and improving the perceived quality of the door lower trim panel assembly.
The left rubber buffer block (NX) is a soft polyurethane block that cushions the door lower trim panel against the door frame. One block is supplied for the left side, preventing the trim panel from rattling when the door is closed. The block has a self‑adhesive backing for easy installation and is designed to compress slightly, providing a snug fit that eliminates movement of the door lower trim panel.
The right rubber buffer block (NX) is the counterpart for the right door, offering the same cushioning and noise‑damping properties. This block is installed at the lower corner of the door inner panel, ensuring that the door lower trim panel remains firmly seated against the sheet metal. The buffer blocks are made from ozone‑resistant rubber that retains flexibility over a wide temperature range.
The lower trim panel strip of left door is the left side version of the bottom edge molding. This strip is essential for completing the appearance of the left door lower trim panel assembly. It is manufactured from the same UV‑stabilized ABS as the right strip and includes pre‑drilled holes for the hexagon flange bolts. The strip also serves as a mounting base for the door scuff plate.
The hexagon bolt with flange (ZQ1840620F31) is a longer version of the M6 flange bolt, with a length of 20mm. Eight bolts are supplied, used where extra reach is needed to pass through thicker trim stacks or into deeper threaded bosses. These bolts are also grade 8.8 with zinc plating and a serrated flange, providing a secure, vibration‑proof attachment for the door lower trim panel components that require deeper engagement.
The large washer (Q402B06F31) is a flat washer with an outer diameter of 18mm and an inner diameter of 6.4mm. Eight washers are included, used under the head of the hexagon bolts to distribute clamping load over a wider area, preventing the bolt head from sinking into soft plastic trim panels. The washers are made from zinc plated steel and are reusable.
The hexagon flower pan head tapping screw is a self‑tapping screw with a Phillips drive and a flower‑shaped head that provides a larger driving surface. Six screws are supplied, each with a sharp point that cuts its own thread in plastic or thin sheet metal. These screws are used to attach the lower trim panel strips and the inner decorative panels without the need for pre‑tapped holes.
The hexagon flange bolt (coarse teeth) (ZQ1840616F31) is a special M6 bolt with a length of 16mm and a coarse, aggressive serration on the flange. Two bolts are supplied, used where maximum resistance to loosening is required, such as at the door handle attachment points. The coarse teeth dig into the mounting surface, creating a positive lock that withstands repeated door slams.
The spring nut (Q39748202F31) is a cage nut that clips into square holes in the door sheet metal. One spring nut is supplied, used to provide a threaded receptacle where the metal is too thin to accept a standard screw. The spring nut is made from hardened spring steel with a zinc coating, and its cage holds the nut in place during assembly, simplifying installation of the door lower trim panel.
Door lower trim panel – complete genuine HOWO interior door component kit
| Material Encoding | Name |
|---|---|
| ZQ1840612F31 | Hexagon bolt with flange |
| YG1671330006 | Lower trim panel strip of right door |
| YG1671330007 | Lower inner trim panel of left door |
| YG1671330002 | Outer lower trim panel of right door |
| YG1671330001 | Outer lower trim panel of left door |
| YG1671330008 | Inner panel of right door lower decorative panel |
| YZ1671330261 | Left Rubber Buffer Block (NX) |
| YZ1671330262 | Right Rubber Buffer Block (NX) |
| YG1671330005 | Lower trim panel strip of left door |
| ZQ1840620F31 | Hexagon bolt with flange |
| Q402B06F31 | Large washer |
| Q27A4816F31 | Hexagon flower pan head tapping screw |
| ZQ1840616F31 | Hexagon flange bolt (coarse teeth) |
| Q39748202F31 | Spring nut |
This door lower trim panel kit includes every plastic trim piece, rubber buffer, and fastener required to restore both front doors. No need to source left and right sides separately; all components are matched for perfect fitment on the HOWO MAX 4X2 cab.
The rubber buffer blocks and the inner fiberboard panel work together to eliminate rattles and absorb road noise. The door lower trim panel assembly contributes to a quieter cabin, enhancing driver comfort.
The kit includes a full assortment of flange bolts, tapping screws, large washers, and a spring nut. All fasteners are corrosion resistant and designed to hold the door lower trim panel securely without loosening.
Every trim panel is molded using the original HOWO tooling, ensuring perfect alignment with door contours and existing mounting holes. No cutting or drilling is required; the door lower trim panel installs using the factory fastening points.
The main trim panels are injection molded from high‑grade polypropylene with 20% talc filler for rigidity. The surface is finished with a grain texture that matches the original dashboard and door uppers, providing a consistent interior appearance. The lower trim panel strips are made from ABS plastic that is UV stabilized to prevent fading and cracking. The rubber buffer blocks are molded from EPDM rubber with a Shore A hardness of 55, providing an optimal balance of cushioning and durability.
Begin by removing the old trim panels and cleaning the door inner surface. Install the rubber buffer blocks on the door sheet metal at the indicated locations. Attach the lower trim panel strips using the hexagon flower pan head tapping screws. Mount the inner decorative panels using the hexagon bolts with flange (12mm length) and large washers. Secure the outer lower trim panels with the longer flange bolts (20mm). Use the spring nut where no threaded hole exists. Finally, install the coarse‑tooth flange bolts at the heavy‑load points. Torque all M6 bolts to 8‑10 Nm; do not overtighten.
This door lower trim panel kit is designed for the HOWO MAX 4X2 standard and sleeper cabs. It fits both left‑hand drive and right‑hand drive configurations, with left and right components clearly marked. The panels are not compatible with the older HOWO 70 series or with 6X4 chassis cabs due to different door geometries. Always verify your vehicle’s cab type before ordering.
Clean the trim panels with a mild soap solution and a soft cloth. Avoid using abrasive cleaners or solvents that may damage the surface grain. Inspect the rubber buffer blocks every 50,000 km; replace them if they become hard or cracked. Check all fasteners for tightness; retorque as needed. If any clip or stud breaks, replace the affected component with a genuine HOWO part to maintain a rattle‑free fit.
If the door lower trim panel rattles, check that all buffer blocks are present and that the tapping screws are tight. If a trim panel does not align with the door contour, verify that the correct left/right part is used. If a bolt spins without tightening, the spring nut may have been dislodged; reposition it using a thin tool. If the large washer is missing, the bolt head may sink into the plastic, causing stress cracks; always use the supplied washers.
Aftermarket trim panels are often made from lower grade plastic that warps in sunlight and fades unevenly. Generic fastener kits may omit the serrated flange bolts or the spring nut, leading to loose panels. The rubber buffer blocks in copy kits are frequently made from cheap foam that compresses permanently. Genuine HOWO door lower trim panel components use the exact materials and manufacturing processes as the original equipment, ensuring perfect fit, long‑term durability, and consistent appearance.
All plastic components are recyclable and marked with resin identification codes. The packaging is made from recycled cardboard and is fully recyclable. The manufacturing facility is ISO 14001 certified. No hazardous substances are used in the production of the door lower trim panel kit.
The complete door lower trim panel kit includes all 14 unique components listed in the parameters table. Individual components can be ordered separately using their material encodings. Authorized HOWO dealers in Nigeria stock these genuine parts. For fleet orders of five or more kits, volume discounts are available. Always provide your vehicle’s VIN to confirm compatibility.
Fleet owners who have installed this genuine HOWO door lower trim panel kit report a dramatic improvement in interior appearance and reduction in door rattles. The rubber buffer blocks have eliminated the annoying squeaks that often develop with age. The precision fit of the trim panels has impressed workshop technicians, reducing installation time. Many operators have standardized on this kit for all HOWO MAX 4X2 tractors in their fleets.
The door lower trim panel kit is shipped in a reinforced cardboard box measuring 120cm x 40cm x 20cm, weight 6 kg. The larger trim panels are wrapped in protective foam. The fasteners are in sealed poly bags. Store the kit in a dry indoor area, away from direct sunlight. Do not stack heavy items on top of the box to prevent warping of the plastic panels. The shelf life is three years when stored properly.
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