FAW Lower Berth Assembly: A 6-Part Breakdown of Your Essential Comfort System

Welcome to this in-depth structural analysis of the FAW Lower Berth Assembly (Assembly 698). This is the complete, 6-component-type, structural foundation for the sleeper bunk in the FAW Jiefang CA4251P66K24T1A3E5 6×4 diesel semi-trailer tractor. This assembly is not the mattress; it is the “logic” system of welded frames, covers, and storage boxes that *create* the “flat floor” living and resting space for the driver.

The “logic” of the FAW Lower Berth Assembly is twofold. First, it is the primary “structural logic,” serving as the load-bearing frame that supports the driver and mattress, adding to the cab’s overall rigidity. Second, it is the “storage logic,” as this framework is engineered to create massive, integrated, and easily accessible storage compartments under the bunk, a critical feature for long-haul comfort.

This expert guide is essential for cab technicians, collision repair specialists, and fleet managers. We will deconstruct the entire FAW Lower Berth Assembly into its 6 distinct serviceable component types. We will analyze the “dual-logic” of the main ‘Welded Support Frames’ (Components 1 & 2), the “load-bearing” logic of the ‘Cover Plate’ (Component 4), the “convenience” logic of the ‘Storage Box’ (Component 5), and the critical “anti-vibration” fastener system.

Core 1: The “Structural Frame” Logic (Components 1 & 2) (The “Longer” Module)

The foundation of the FAW Lower Berth Assembly is its “skeleton.” This is comprised of the ‘Left sleeper support frame welded assy’ (7007010-A09, etc.) and the ‘Right sleeper support frame welded assy’ (7007040-A09, etc.). These are the primary structural components.

1. The “Load-Bearing” Logic:

This is the “chassis” of the bunk. This “logic” is to provide an unyielding, rigid foundation. This welded steel frame must support the static weight of the mattress and one or two resting drivers (150kg+), *plus* the dynamic G-forces of the cab bouncing on the highway.

This frame is fabricated from high-strength, precision-welded steel. It is the “logic” component that provides the torsional rigidity (resistance to twisting) for the entire sleeper compartment. It is securely fastened (using MSU 3) to the ‘Welded Cab Assembly’ (Assembly 617) rear bulkhead and floor.

2. The “Integrated Storage” Logic:

The “logic” of this frame is not just support; it is *space creation*. The welded frame is not a solid block; it is an open “truss” structure. This design “logic” is what *creates* the large, open, and secure storage bays under the bunk. This is the most valuable space in a long-haul cab, and this FAW Lower Berth Assembly is engineered to maximize it.

3. The “Variant & Service” Logic:

The parts list shows *five different part numbers* for the Left/Right frames (A09, AB27, CB27, etc.). This “variant logic” is critical for parts managers. These different frames are designed for different cab configurations. For example, a cab *with* an “independent heater” (like Assembly 692) or a factory-installed refrigerator will require a frame with *different mounting points* and cutouts.

As serviceable parts, these welded frames are the primary components replaced after a severe collision (especially a rear-end or side-impact) that has compromised the cab’s structural integrity. A bent frame will cause the storage lids (Component 4) to bind and the bunk to be un-level.

Core 2: The “Modular Storage” Logic (Components 4 & 5)

This group of components provides the “user-facing” part of the FAW Lower Berth Assembly storage system.

Component 4: ‘Right upper cover plate assy’ (7007130-A01): This is the “logic” of “access.” This is the large, flat, structural “lid” that covers the storage bay created by the ‘Right support frame’ (Component 2).

This component’s “logic” is twofold: 1) It is a “lid” that is hinged to provide access to the storage below. 2) It is also the “floor” of the bunk. It is a load-bearing panel, reinforced with stamped ribs on its underside, to be strong enough to support the mattress and driver without “sagging” or “flexing.”

Component 5: ‘Storage box assy I-sleeper’ (7007110-A01): This is the “convenience” logic. While Component 4 is a “lid,” this is a complete, pre-molded “tub” or “box.” This “logic” is to provide a “clean” storage area, often for the ‘On-board Tools’ (Assembly 598).

This polymer box is a “drop-in” serviceable part. Its “logic” is to isolate its contents (tools, straps) from the “carpeted” main area, making it durable and easy to clean. This modularity is a key part of the FAW Lower Berth Assembly.

Core 3: The “Anti-Rattle” Fastener Logic (Components 3 & 6)

This final group is the “NVH logic” that holds the FAW Lower Berth Assembly together and ensures a silent ride. A “rattling” sleeper bunk is a non-starter for driver comfort.

Component 3: ‘Hexagon nut’ (CQ34006) – Qty 14: This is the “structural” fastener logic. These 14 nuts are what secure the ‘Left’ and ‘Right Support Frames’ (Components 1 & 2) to the ‘Welded Cab Assembly’ (617) floor/wall.

These are high-tensile, “prevailing-torque” (Nyloc) lock nuts. Their “logic” is to be *immune to vibration*. A standard nut *would* vibrate loose. This self-locking design is a critical, single-use safety component.

Component 6: ‘…Combination screw’ (Q2360620F6) – Qty 8: This is the “anti-rattle” logic for the *storage*. These 8 screws are what fasten the ‘Storage box’ (Component 5) and the hinges for the ‘Cover plate’ (Component 4) *to* the welded frame.

A “Combination” (组合) screw has a captive, pre-attached *lock washer*. This “logic” provides constant tension, preventing the plastic box and lids from “buzzing” or “rattling” against the metal frame. This ensures the FAW Lower Berth Assembly is absolutely silent.

FAW Lower Berth Assembly Parts List & Specifications

The following table provides the complete, detailed breakdown of all 6 component types identified in the FAW Lower Berth Assembly diagram for the FAW CA4251P66K24T1A3E5 tractor.

Specifications

The specifications for the FAW Lower Berth Assembly are defined by its function as a structural, load-bearing, and modular storage system for the sleeper cab.