FAW Dual-Axis Assembly: A Complete Analysis of Its 17 Основные компоненты

Welcome to this complete technical analysis of the FAW Dual-Axis Assembly, also known as the transmission main shaft or “второй вал,” для FAW Jiefang CA4251P66K24T1A3E5 6×4 дизельный полуприцеп тягач. This component is the primary output shaft of the transmission’s main box.

The FAW Dual-Axis Assembly is responsible for holding all the “управляемый” шестерни (1ул, 2н.д., 3р-д, 4й, 5й, and reverse) and the synchronizer “sliding sleeves” that lock them in place. It receives torque from the counter-shaft and transmits the selected gear ratio to the truck’s driveline.

This guide is an essential resource for professional transmission rebuilders and parts specialists. Мы разберем всю FAW Dual-Axis Assembly в свой 17 исправные компоненты, including the main shaft (1701301-А9К), all individual helical gears, the sliding sleeves, and the critical bearings and circlips that maintain perfect alignment.

Основной компонент: The Second Shaft (1701301-А9К)

The backbone of the FAW Dual-Axis Assembly is the ‘Second shaft’ (1701301-А9К), also known as the main shaft. Это сингл, massive, forged component made from high-strength, case-hardened steel. It is designed to withstand the full, multiplied torque of the engine’s output.

The function of this shaft is to act as the “выход” shaft of the main gearbox. Unlike the counter-shaft (which is always spinning at a fixed ratio to the engine), а FAW Dual-Axis Assembly‘s speed *changes* based on the gear selected.

This shaft is a complex piece of precision machining. It features a long, splined section where the synchronizer hubs (sliding sleeves) are fixed. It also has multiple, mirror-smooth journals where the “freewheeling” driven gears ride on needle bearings. The front “nose” of this shaft fits into the “pilot bushing” (1701111-A7G) inside the input shaft, ensuring perfect alignment. A bent or twisted main shaft will cause catastrophic gear failure, making the integrity of the FAW Dual-Axis Assembly paramount.

The “Driven” Gears: Constant-Mesh Logic

The core “логика” принадлежащий FAW Dual-Axis Assembly is its “constant-mesh” дизайн. This parts list details all the “управляемый” шестерни, which are in permanent, constant mesh with the “водить машину” gears on the counter-shaft. These gears are:

• ‘First gear-second shaft’ (1701326-А9К)
• ‘Second gear-second shaft’ (1701356-А9К)
• ‘Third gear-second shaft’ (1701366-А9К)
• ‘Fourth gear-second shaft’ (1701386-А9К)
• ‘Fifth gear-second shaft’ (1701323-A1K)
• ‘Reverse gear-second shaft’ (1701311-A7G)

When the truck is in neutral, the clutch is engaged, and the input shaft is spinning the counter-shaft. This means all of these driven gears are *also* spinning, but because they ride on bearings on the ‘Second shaft’, they are “freewheeling.” They are not locked to the FAW Dual-Axis Assembly, so no power is transmitted.

When the driver selects a gear (НАПРИМЕР., 3р-д), the shift fork moves a ‘Sliding sleeve’ (1701316-A7G), which locks the ‘Third gear-second shaft’ (1701366-А9К) к FAW Dual-Axis Assembly. At that moment, power flows from the counter-shaft, through the 3rd gear pair, and onto the FAW Dual-Axis Assembly (main shaft), which then spins at the 3rd gear ratio. All other gears on the shaft continue to freewheel.

The “Логика” Компоненты: Sliding Sleeves (1701316-А9К / A7G)

The “логика” of gear selection in the FAW Dual-Axis Assembly is performed by the ‘Sliding sleeve’ (1701316-А9К) and ‘Sliding sleeve’ (1701316-A7G) единицы. The list calls for a total of four (one -A9K, three -A7G). These are the synchronizer hubs.

Each sliding sleeve is what the driver’s shift fork physically moves. The *inside* of the sleeve is splined and is permanently locked to the FAW Dual-Axis Assembly (main shaft). The *outside* of the sleeve is a groove for the shift fork. When the driver moves the shifter, this sleeve slides “вперед” или “backward” on the shaft.

The sides of the sleeve, and the sides of the freewheeling gears, have a set of “зубы собаки” (или “clutching teeth”). When the sleeve slides over, its internal teeth engage with the dog teeth on the side of the gear. This creates a solid, positive lock, forcing the freewheeling gear to spin at the same speed as the FAW Dual-Axis Assembly.

To prevent a “grinding” сдвиг, this sleeve assembly also contains a “синхронизатор” (или “блокирующее кольцо”). This is a tapered bronze ring that acts as a small, cone-shaped clutch. As the sleeve moves forward, it first pushes this bronze ring onto a matching cone on the gear. The friction between the two instantly equalizes the speed of the sleeve (spinning at shaft speed) and the gear (freewheeling at a different speed). Once their speeds are matched, the sleeve can slide over the dog teeth smoothly and silently. Этот “sync-then-lock” logic is the genius of the FAW Dual-Axis Assembly.

Precision Alignment: Washers and Circlips

A constant-mesh gearbox requires perfect alignment. The gears on the FAW Dual-Axis Assembly must be perfectly aligned with their counterparts on the counter-shaft. This alignment, или “end-play,” is controlled by a system of precision washers and circlips.

The parts list calls for five ‘Limit washer – механизм’ (1701327-A7G) and three ‘Inter-shaft limit washer’ (1701318-A9K/A7G). These are not standard washers. Они есть “shims”—hardened, precision-ground washers of a very specific thickness. They are placed between the freewheeling gears and their synchronizer hubs to control the “end-play” (the fore-and-aft slop).

Сходным образом, the ‘Locating retaining ring-reverse gear’ (1701312-A7G) and ‘Limit washer-reverse gear’ (1701313-A7G) are a matched set. They work together to lock the ‘Reverse gear-second shaft’ (1701311-A7G) in its exact position on the FAW Dual-Axis Assembly, ensuring it aligns perfectly with its idler gear.

The ‘Three-sided key’ (1701396-А9К) and its ‘Circlip’ (1701333-A7G) are used to permanently lock a main synchronizer hub to the FAW Dual-Axis Assembly, while the ‘Spring dowel pin’ (Q5280310) is likely used to lock a shaft or pin in place. This entire system of small parts is what guarantees the quiet, long-lasting, and precise operation of the FAW Dual-Axis Assembly.

FAW Dual-Axis Assembly Parts List

В следующей таблице представлена ​​полная, подробная разбивка всех 17 components identified in the ‘Dual-Axis (Second Shaft) Сборка’ схема трактора FAW CA4251P66K24T1A3E5. A rebuild of the FAW Dual-Axis Assembly requires meticulous attention to the placement of each washer and circlip.

Технические характеристики и контекст сборки

Технические характеристики FAW Dual-Axis Assembly are defined by its function as the transmission’s main output shaft, which holds all the freewheeling “управляемый” gears and the synchronizer hubs. The proper shimming of the FAW Dual-Axis Assembly имеет решающее значение.