FAW J6P First Axis: Deconstructing 8 Critical Parts for Flawless Torque Input

Welcome to this in-depth deconstruction of the FAW J6P First Axis (Gearbox Input Shaft), a core component of the CA10TA160M transmission for the FAW Jiefang CA3250P66K2L1T1E 6×4 dump truck. This guide is for technicians, analyzing the 8 critical components that make up the complete FAW J6P First Axis assembly, from the shaft itself to its essential bearings.

The FAW J6P First Axis is the “front door” of the gearbox. Its logic is to receive 100% of the engine’s power from the clutch and transfer it to the countershafts. Its integrity, alignment, and sealing are paramount for a quiet, reliable, and leak-free transmission. This guide explores each component’s logic.

Core 1: The “Shaft & Drive Gear” Logic (The FAW J6P First Axis)

This group represents the “spine” and “output” of the FAW J6P First Axis assembly. It is responsible for both receiving power from the clutch and delivering it to the gearbox’s internal gear train.

1. Component: ‘First shaft – gearbox’ (1701112-A1K / 1701112-A7G)
This (Comp 6) is the primary shaft, the FAW J6P First Axis itself. It is a single, heavy-duty component, precision-machined from hardened steel to withstand immense torsional forces. Its logic is to act as the “bridge” between the engine’s clutch and the transmission’s countershafts.

The Input Spline Logic is its first function. The front end of the shaft (projecting into the bellhousing) is externally splined. These splines mate perfectly with the internal splines of the ‘Clutch driven plate’ (clutch disc). This is the “input” point, where 100% of the engine’s torque is transferred to the FAW J6P First Axis.

The Shaft Support Logic defines its middle section. This smooth, machined surface is where the main ‘Ball bearing’ (Comp 2) is pressed, supporting the entire shaft assembly within the gearbox housing. The ‘Oil seal’ (Comp 1) also rides on this surface.

The two part numbers (A1K and A7G) likely indicate a minor design change, material specification, or supersession. The note “(Rotates with 1601010D76A)” is a bit confusing, as 1601010D76A is the clutch housing; this shaft rotates *with the clutch disc*, not the housing. The core function of the FAW J6P First Axis is to spin *independently* of the housing when the clutch is disengaged.

2. Component: ‘Input gear – first shaft’ (1701121-A7G)
This (Comp 8) is the main drive gear for the entire CA10TA160M transmission. It is the “output” of the FAW J6P First Axis assembly. This gear is either pressed or splined onto the rear of the ‘First shaft’ (Comp 6) and is considered an integral part of its assembly.

The Constant Mesh Logic is its function. This gear’s teeth are in constant, permanent mesh with the main drive gear(s) on the transmission’s countershaft(s). Any time the clutch is engaged and the FAW J6P First Axis is spinning, this gear is spinning and actively driving the countershafts. This provides the power input to the entire gear train.

Core 2: The “Pilot & Alignment” Logic (The Bushing)

This component is a small but dimensionally critical part of the FAW J6P First Axis. Its logic is to ensure perfect alignment between the spinning input shaft and the separate, concentric mainshaft.

1. Component: ‘Bushing’ (1701111-A7G)
This (Comp 7) is a “pilot bushing” or “spigot bearing.” It is a small, hollow cylinder, typically made of bronze or a similar low-friction alloy. It is pressed into a precisely-bored recess in the *rear* end of the ‘Input gear’ (Comp 8) or ‘First shaft’ (Comp 6).

The Concentricity Logic is its sole purpose. The transmission’s mainshaft (which holds all the gears) is a separate shaft that needs to be perfectly aligned with the FAW J6P First Axis. The “tip” of this mainshaft slides *into* this ‘Bushing’.

This bushing acts as a crucial support, allowing the FAW J6P First Axis to spin around the mainshaft tip (when the clutch is disengaged) without any “wobble” or “runout.” A worn-out pilot bushing (Comp 7) will cause severe vibration, difficulty in shifting, and will rapidly destroy the mainshaft bearings and synchronizers.

Core 3: The “Main Bearing & Seal” Logic (Front Assembly)

This group is the primary “gateway” between the FAW J6P First Axis and the outside world. It is responsible for supporting the entire shaft assembly and, most importantly, keeping the oil inside the gearbox.

1. Component: ‘Deep groove ball bearing with stop ring’ (6212-ZNBR/C3YB2)
This (Comp 2) is the main bearing for the FAW J6P First Axis. This is a high-load, precision ball bearing that is pressed onto the ‘First shaft’ (Comp 6) and then fits into the main bore of the ‘Gearbox Housing’.

The Support Logic is clear: it supports the radial (up/down) and axial (in/out) loads placed on the FAW J6P First Axis by the clutch and the gear mesh. The ‘C3’ designation indicates a specific internal clearance, designed to accommodate the high temperatures and thermal expansion inside a gearbox.

The Stop Ring Logic (ZNBR) is critical. This bearing has a built-in “snap ring” on its *outer* race. This ring fits into a groove in the gearbox housing, physically locking the bearing in place and preventing the entire FAW J6P First Axis from moving forward or backward.

2. Component: ‘Oil seal – first shaft’ (1701135-A7G)
This (Comp 1) is the main input shaft oil seal. It is a “no-leak” component, typically pressed into the ‘Bearing cover’ (part of the gearbox housing) which is located *in front* of the main bearing (Comp 2).

The Sealing Logic is to keep two different environments separate. The “lip” of this seal rides on the spinning surface of the FAW J6P First Axis, keeping the high-temperature gear oil *inside* the gearbox. Simultaneously, it keeps the “dry” bellhousing free of oil, dust, and contaminants.

A failure of this one seal is catastrophic. It will leak gear oil directly onto the clutch assembly. This oil will saturate the clutch disc, causing massive slippage, a “burning clutch” smell, and a complete loss of power. It is a primary service item during any FAW J6P First Axis or clutch service.

Core 4: The “Rear Retention & Shimming” Logic

This final group of components is responsible for the precise positioning of the FAW J6P First Axis and its associated bearings and gears. Their logic is all about managing “end play” and “clearances.”

1. The “Rear Bearing” Group (Comp 3 & 4)
This group includes: ‘Snap ring – first shaft rear bearing’ (1701131-A7G, 1701132-A7G, etc.) and ‘Gasket – first shaft rear bearing’ (1701123-A7G).

The Shimming Logic is the function of this group. The FAW J6P First Axis must have a tiny, precise amount of “end play” (in-and-out movement), often just a few thousandths of an inch. Too little, and thermal expansion will destroy the bearings. Too much, and the gear mesh will be incorrect.

The four different ‘Snap rings’ (Comp 3) are not used all at once. They are a “shim pack.” A technician measures the gap and selects the *one* ‘Snap ring’ with the correct thickness to achieve the perfect end play. The ‘Gasket’ (Comp 4) is part of this calculation, setting the position of the bearing race. This is a high-precision task for a FAW J6P Gearbox rebuild.

2. The “Gear Hub” Group (Comp 5)
This component is the ‘Snap ring – gear hub’ (1701314-A7G). This is a different type of snap ring.

The Positioning Logic is its function. This snap ring (Comp 5) fits into a groove machined directly *on* the FAW J6P First Axis (Comp 6). Its purpose is to act as a “hard stop” or “locator.” It ensures that the ‘Input gear’ (Comp 8) or a synchronizer hub slides onto the shaft and stops at the exact correct position, ensuring perfect alignment with the countershaft gears.

FAW J6P First Axis: Complete 8-Part Breakdown

The following table provides the complete, detailed breakdown of all 8 component types in the FAW J6P First Axis assembly for the FAW Jiefang CA3250P66K2L1T1E 6×4 dump truck.

Core Specifications

The specifications for the FAW J6P First Axis assembly are defined by its function as the primary input shaft for the CA10TA160M gearbox, engineered for high-torque and reliability.