FAW Front Suspension: A Critical Focus on 38 Serviceable Parts

Welcome to this critical technical guide on the FAW Front Suspension (Assembly 508). This is the complete, multi-part system responsible for supporting the entire front-end load of the FAW Jiefang CA4251P66K24T1A3E5 6×4 diesel semi-trailer tractor. This assembly is the critical link between the chassis, the front axle, and the road.

The FAW Front Suspension is a “logic” system with three primary functions: to bear the massive weight of the engine and cab via the ‘Front leaf spring assembly’ (2902010A50A), to control and dampen suspension movement via the ‘Front shock absorber assembly’ (2905010-1086), and to provide lateral stability and control body roll via the ‘Front lateral stabiliser bar assy’ (2906010-1063).

This in-depth guide is an essential resource for professional suspension technicians and fleet managers. We will deconstruct the entire FAW Front Suspension system into its 38 serviceable components, explaining the function of each interconnected part, from the U-bolts that hold the axle to the brackets that support the shock absorbers and stabilizer bar.

Core Logic 1: The Leaf Spring Assembly (2902010A50A)

The heart of the FAW Front Suspension is the ‘Front leaf spring assembly’ (2902010A50A), of which there are two. This is the primary load-bearing component. It is not a single piece of steel, but a “pack” of multiple, stacked “leaves” made of high-carbon spring steel. This parts list breaks down the pack into its individual components, such as ‘Front leaf spring-first leaf’ (2902011A50A), ‘Front leaf spring-second leaf’ (2902012A50A), and ‘Front leaf spring-third leaf’ (2902013A50A).

This multi-leaf “logic” is what provides a **progressive spring rate**. When the truck is unladen, only the top, longer leaves flex, providing a (relatively) softer ride. As the truck is loaded or hits a large bump, the load is transferred to the shorter, thicker leaves, dramatically increasing the stiffness and preventing the suspension from “bottoming out.”

This pack is held together by the ‘Center bolt-front leaf spring’ (2902161-40A) and kept in alignment by ‘Clips’ (2902131-50A). To prevent metal-on-metal friction and squeaking, the assembly uses eight ‘Damping pad-front leaf spring’ (2902137A50A) units, which are small polymer pads that allow the leaves to slide smoothly against each other. The ‘Bushing-rear leaf spring’ (2912121-03) and the ‘Front leaf spring first leaf & bushing assembly’ (2902105A50A) are the rubber/bronze pivot points in the “eyes” of the spring, isolating vibration from the FAW Front Suspension frame.

Core Logic 2: The Damping System (Shock Absorbers)

The leaf springs in the FAW Front Suspension are excellent at supporting weight, but they are not designed to stop bouncing. This is the job of the ‘Front shock absorber assembly’ (2905010-1086). The parts list calls for two.

The “logic” of a shock absorber is to **dampen oscillation** by converting kinetic energy (bouncing) into heat. It is a hydraulic piston that forces oil through small, precise valves. As the leaf spring compresses and rebounds, the shock absorber resists this movement, “killing” the bounce and keeping the truck’s tires firmly planted on the road. Without the shock absorbers, the truck would be dangerously unstable, with no reliable steering or braking.

The FAW Front Suspension provides the mounting points for this system. The ‘Lower left support bracket assy-front shock absorber’ (2905425-2000) and ‘Lower right support bracket assy-front shock absorber’ (2905430-2000) are the heavy-duty brackets on the axle. The ‘Hex head guide bolts’ (CQ15116120T, CQ15116140T) and ‘Large washers’ (Q40216) are the precision fasteners used to mount the shocks to these brackets, as detailed in Assembly 505.

Core Logic 3: The Stabilizer Bar System (Anti-Roll)

The final “logic” of the FAW Front Suspension is to control **lateral stability** (or “body roll”). This is the job of the ‘Front lateral stabiliser bar assy’ (2906010-1063), also known as the “anti-roll bar” or “sway bar.”

This is a single, U-shaped torsional spring. Its logic is to connect the left and right sides of the suspension *indirectly*. When the truck corners, the cab “leans,” compressing the outside spring. This “twist” is transferred along the stabilizer bar, which then *pulls down* on the *inside* of the suspension, forcing the cab to stay level.

This FAW Front Suspension parts list includes all the mounting components for this system. The ‘Bracket-front lateral stabilizer’ (2906444-50A) and its ‘Cover’ (2906446-50A) and ‘Bushing’ (2906447-50A) are used to mount the main bar to the truck’s frame. The ‘Boom & bushing assy-front lateral stabiliser bar’ (2906320-92V) are the “end links” that connect the “arms” of the bar to the axle, completing the system.

The Axle Connection: U-Bolts (2902411-92V)

The single most critical connection in the FAW Front Suspension is how the leaf spring pack attaches to the solid front axle. This is accomplished by the ‘U-bolt-front leaf spring’ (2902411-56B and 2902411-92V). The list calls for two of each, for a total of four U-bolts (two for each spring pack).

These are not standard bolts. They are high-tensile, forged steel U-bolts that “hook” *under* the axle and pass *up* through the ‘Cover-front leaf spring’ (2902406A50A), which is a heavy-duty cap that sits on top of the spring pack.

The eight ‘Nut-fasten U-bolt’ (2902413-76A) are then used to tighten this “sandwich” (Cover – Spring Pack – Axle) together with thousands of pounds of clamping force. This is what prevents the front axle from “walking” or “shifting” under the truck. A loose U-bolt is a critical safety failure, leading to a loss of steering control. The ‘Soft pad-front leaf spring’ (2902432-50A) is a rubber insulator pad that sits between the spring pack and the axle seat to reduce vibration. This entire “clamping logic” is a core part of the FAW Front Suspension.

FAW Front Suspension Parts List

The following table provides the complete, detailed breakdown of all 38 components identified in the ‘Front Suspension’ (508) diagram for the FAW CA4251P66K24T1A3E5 tractor. This FAW Front Suspension assembly is a complete system.

Technical Specifications and Assembly Context

The specifications for the FAW Front Suspension are defined by its function as a complete, heavy-duty suspension and damping system. The entire FAW Front Suspension assembly is a safety-critical system.