FAW Driveshaft Assembly Diagram: Why These 5 Critical Components Matter for Torque Transfer

Welcome to this critical technical guide to the FAW Driveshaft Assembly Diagram. This assembly, also known as the “propeller shaft” or “propshaft,” is the complete system for transmitting power from the transmission to the drive axles on the FAW Jiefang CA4251P66K24T1A3E5 6×4 diesel semi-trailer tractor.

The FAW Driveshaft Assembly Diagram illustrates a system of two main shafts: a main driveshaft from the gearbox to the first rear axle, and an inter-axle driveshaft connecting the two rear axles. This system must handle 100% of the engine’s multiplied torque while constantly flexing with the truck’s suspension.

This in-depth guide is an essential resource for professional technicians and fleet managers. We will deconstruct the entire FAW Driveshaft Assembly Diagram into its 5 serviceable component types, including the ‘Inter-axle driveshaft’ (2205010A91W), the ‘Rear-axle driveshaft’ (2201010-1050), and the critical high-torque fasteners that secure them.

Core Component 1: The Main Driveshaft (2201010-1050)

The ‘Rear-axle driveshaft & universal joint assembly’ (2201010-1050), despite its name, is the **main driveshaft**. It is the primary component in the FAW Driveshaft Assembly Diagram that connects the transmission’s output flange to the “forward” (or “middle”) drive axle’s input flange.

This component is a precision-engineered, hollow steel tube. It must be both incredibly strong (to handle the engine’s full torque) and perfectly balanced. Any imbalance in this long, high-speed shaft would create a severe, speed-dependent vibration that would shake the entire truck and destroy the transmission’s output bearing. It is dynamically balanced at the factory to a very high tolerance.

A critical design element is its “critical speed”—the RPM at which a shaft’s own harmonic frequency will cause it to wobble violently, like a jump rope. This FAW Driveshaft Assembly Diagram component is engineered with a specific diameter and wall thickness to ensure its critical speed is far higher than the truck will ever achieve.

Core Component 2: The Inter-Axle Driveshaft (2205010A91W)

The ‘Inter-axle driveshaft & universal joint assembly’ (2205010A91W) is the second shaft in this 6×4 system. This is the “inter-axle” shaft, a key part of the FAW Driveshaft Assembly Diagram. Its job is to connect the “output” of the forward-most drive axle to the “input” of the rear-most drive axle.

This allows the engine’s torque to be “passed through” the first axle to power the second, ensuring all four sets of rear wheels are driven (the “4” in 6×4). This short, high-torque shaft must handle the same immense forces as the main shaft.

Both this shaft and the main shaft are listed as an “assembly” because they come as a complete, non-serviceable unit with the ‘Universal Joint Assemblies’ (U-Joints) factory-installed and balanced. A failure of a U-joint on this FAW Driveshaft Assembly Diagram component typically requires the replacement of the entire shaft assembly.

The “Logic”: Understanding the Universal Joints (U-Joints)

The “logic” of the FAW Driveshaft Assembly Diagram is embodied by its universal joints, which are included in the shaft assemblies. A U-joint is a simple, brilliant piece of engineering that allows a shaft to transmit full rotational power even when it is bent at an angle.

This is necessary because the transmission is fixed to the engine, while the drive axles are on the suspension, constantly moving up and down. The angle between the transmission and the axle is never the same. A U-joint solves this by acting as a “double-hinge.”

It consists of a central “cross” or “spider” with four precision-ground trunnions (arms). Each trunnion is fitted with a “cap” containing needle-roller bearings. These four caps are then bolted into the “yokes” (the U-shaped ends) of the two shafts. This allows the FAW Driveshaft Assembly Diagram to “bend” in two axes (up/down and left/right) simultaneously, all while spinning at thousands of RPM.

A critical aspect of the FAW Driveshaft Assembly Diagram is **”phasing.”** The yokes at both ends of a single shaft must be installed in perfect alignment. If they are “out of phase” (misaligned), the U-joints will not cancel each other’s vibrations, leading to a severe “shudder” on acceleration and rapid failure.

The primary failure mode for a U-joint in the FAW Driveshaft Assembly Diagram is lack of lubrication. The needle bearings inside the caps require periodic greasing. If they run dry, they will be destroyed by friction, causing a “chirping” noise (that varies with road speed) or a “clunk” when shifting from drive to reverse. A seized U-joint will cause a catastrophic failure, often breaking the driveshaft and potentially damaging the transmission housing.

Critical Fasteners: The 32-Piece Flange Hardware Set

The FAW Driveshaft Assembly Diagram lists a large quantity of specialized, high-strength hardware. This is because the entire torque of the engine is transmitted through these few bolts.

**Bolts (Q1851455T & Q1851450T):** The list calls for 8 ‘Hex head flange bolts’ (Q1851455T) and 8 ‘Hex head flange bolts’ (Q1851450T). This is a total of 16 bolts. This makes perfect sense for a two-shaft system:

• 4 bolts for the Transmission-to-Main-Shaft flange.
• 4 bolts for the Main-Shaft-to-First-Axle flange.
• 4 bolts for the First-Axle-to-Inter-Axle-Shaft flange.
• 4 bolts for the Inter-Axle-Shaft-to-Second-Axle flange.

These are “flange” bolts, and the “T” suffix indicates they are high-tensile (e.g., Class 10.9 or 12.9) and designed to withstand extreme “shear” forces. The two different part numbers refer to different lengths, as the transmission flange and axle flanges may have different thicknesses.

**Nuts (Q32914):** The ‘Type 1 non-metallic insert hex lock nut’ (Q32914) is the final piece of the FAW Driveshaft Assembly Diagram. The list calls for 16 nuts to match the 16 bolts. These are “Nyloc” nuts. The nylon insert at the top of the nut creates a “prevailing torque,” which grips the bolt threads and prevents the nut from *ever* vibrating loose. This is a critical, single-use safety feature. These nuts must be replaced every time they are removed to ensure the FAW Driveshaft Assembly Diagram remains secure.

FAW Driveshaft Assembly Diagram Parts List

The following table provides the complete, detailed breakdown of all 5 component types identified in the ‘Driveshaft Assembly Diagram’ for the FAW CA4251P66K24T1A3E5 tractor. This FAW Driveshaft Assembly Diagram is the complete torque transfer system.

Technical Specifications and Assembly Context

The specifications for the FAW Driveshaft Assembly Diagram are defined by its function as a high-torque, high-speed, flexible power transmission system. This FAW Driveshaft Assembly Diagram details the complete driveline.