FAW Front Mudguard Logic Assembly: The 5 Critical Components for a Flawless, Secure Cab

Welcome to this in-depth technical analysis of the FAW Front Mudguard Logic Assembly (Assembly 708). This is the complete, 5-component-type, “upper wheel arch” system for the FAW Jiefang CA4251P66K24T1A3E5 6×4 diesel semi-trailer tractor. This assembly is a critical “logic” system with a dual-function: 1) to act as a “splash shield,” protecting the cab and mirrors from road debris, and 2) to act as an “aerodynamic fairing,” smoothing airflow to reduce drag and wind noise.

The “logic” of the FAW Front Mudguard Logic Assembly is a “modular” and “sacrificial” design. It consists of a heavy-duty, internal “steel skeleton” (the ‘Support Brackets’) that bolts rigidly to the cab. The visible, external “skin” (the ‘Mudguard’ panels) is a lightweight, flexible polymer. This “logic” ensures that in a minor collision or from a tire blowout, the “sacrificial” polymer panel is destroyed, while the structural steel brackets and the cab itself are protected, dramatically reducing repair costs.

This expert guide is an essential resource for collision repair specialists and parts managers. We will deconstruct this entire assembly into its 5 distinct serviceable component types. We will analyze the “protection & aero logic” of the main polymer panels, the “structural logic” of the 4-piece steel sub-frame, and the “anti-vibration logic” of the massive 32-piece fastener system.

Core 1: The “Sacrificial Skin” Logic (Components 1 & 2) (The “Longer” Module)

The primary components, and the main “sacrificial” serviceable parts, are the ‘Left upper mudguard’ (5103161-A01) and the ‘Right upper mudguard’ (5103162-A01). These are the large, visible panels that sit above the front steer tires, integrated with the ‘Wing Panel’ (Assembly 622) below them.

1. The “Protection & Safety” Logic:

This is the #1 “logic” of this assembly. The front steer tires rotate at high speed, picking up and “flinging” a constant barrage of road debris. This mudguard acts as the primary “splash shield.”

Safety Logic: Its first job is to protect *other drivers*. It blocks the “rooster tail” of water spray that can blind adjacent cars. Its second job is to protect the *driver’s* vision, by shielding the ‘Side Window’ (634) and ‘Wing Mirrors’ (702/703) from mud and spray.

Protection Logic: This panel is the “armor” for the ‘Welded Cab Assembly’ (617) A-pillar and door. It stops rocks and gravel from “sandblasting” the paint, preventing rust. It also protects the ‘Side Deflector’ (643) and the door’s seals from being torn or damaged.

2. The “Material & Aero” Logic:

These panels are not metal. They are molded from a high-impact, flexible, UV-stabilized polymer. This “material logic” is superior for this high-impact zone:

• Flexibility: It can be struck by a rock or tire fragment and “flex,” absorbing the impact without denting or cracking.
• Corrosion-Proof: It is 100% immune to the rust and road salt that would destroy a steel panel.
• Aerodynamic: The polymer can be molded into a complex, “curved” fairing. This “aero logic” smooths the turbulent air coming off the front of the tire, reducing drag and wind noise (NVH).

3. The “Serviceability” Logic:

This mudguard is the most likely component to be damaged in a minor collision or a tire blowout. The “modular logic” of this assembly means that this “sacrificial” polymer panel can be unbolted and replaced in minutes, saving the fleet a costly repair to the cab’s main body.

Core 2: The “Structural Skeleton” Logic (Components 3 & 4)

This group of components is the “skeleton” of the assembly. This is the heavy-duty, 4-piece, fabricated steel framework that the “skin” (Components 1 & 2) bolts onto.

Component 3: ‘Upper mudguard front support bracket assy’ (5103140-A01) – Qty 2

Component 4: ‘Upper mudguard rear support bracket assy’ (5103150-A01) – Qty 2

The “Logic” of the 4-Point Frame: The “logic” here is to create a rock-solid, “4-point” sub-frame (a front and rear bracket for each mudguard) that bolts directly to the ‘Welded Cab Assembly’ (617).

These “welded assy” (焊接总成) components are the “chassis” of the mudguard. Their “logic” is to provide the absolute rigidity needed to support the large, flexible polymer panels. They prevent the mudguards from “flapping” or “vibrating” at highway speeds, which would quickly lead to fatigue failure. They are the “anchor” that all road forces are transferred to.

As serviceable parts, these brackets are replaced after a collision has bent them, as a bent bracket will make it impossible to align the new mudguard panel correctly.

Core 3: The “Anti-Rattle” Fastener Logic (Component 5)

The final component is the ‘Combination bolt’ (CQ1460616B). The parts list calls for thirty-two (32) of these.

The “Logic” of 32 Bolts: This high quantity is the “anti-flex” and “anti-rattle” logic. It means that *each* mudguard (Left and Right) is secured to its front/rear brackets by a **16-point** fastener pattern.

This high-density “quilting” pattern is the “logic” that makes the “soft” flexible polymer panel (Component 1/2) act as one “solid,” rigid unit with the “hard” steel frame (Component 3/4). This is the key to preventing the “drumming” noise and vibration that would otherwise plague such a large, flat panel.

The “Combination” Logic: The “Combination” (组合) designation is the “anti-vibration” logic. These are not standard bolts. Each one has a *captive, pre-attached lock washer* (e.g., a serrated or spring washer). This lock washer “bites” into the bracket, providing constant tension that makes the fastener *immune* to vibration. This is a critical serviceable part that ensures the mudguard does not shake itself loose.

FAW Front Mudguard Logic Assembly Parts List

The following table provides the complete, detailed breakdown of all 5 component types identified in the FAW Front Mudguard Logic Assembly for the FAW CA4251P66K24T1A3E5 tractor.

Specifications

The specifications for the FAW Front Mudguard Logic Assembly are defined by its function as a modular, structural “splash shield” and “aerodynamic fairing” for the front wheel arch.