Логика коробки передач заднего моста FAW в сборе: Почему эти 39 Критические детали определяют крутящий момент и тягу

Welcome to this critical technical guide on the Логика коробки передач заднего моста FAW в сборе (Часть №. 2402010QA6T). This is the complete “differential” или “carrier” assembly for the FAW Jiefang CA4251P66K24T1A3E5 6×4 diesel semi-trailer tractor. This assembly is the “brain” of the drive axle, responsible for both the final gear reduction and traction management.

The Логика коробки передач заднего моста FAW в сборе has two vital functions. First, его “reduction gearbox” (the ring and pinion) provides the final torque multiplication (with an io=2.867 ratio). Second, его “логическая сборка” (the differential lock) allows the driver to pneumatically lock the axles, forcing both wheels to spin at the same speed for maximum traction.

This in-depth guide is an essential resource for professional driveline technicians and parts specialists. We will deconstruct the entire Логика коробки передач заднего моста FAW в сборе into its 39 serviceable components, including the main housing, the ring/pinion set, the differential lock mechanism, and the critical bearings and shims.

Core Component: The Axle Housing Assembly (2402015-A6T)

The foundation of the Логика коробки передач заднего моста FAW в сборе is the ‘Rear axle reduction gearbox housing assembly’ (2402015-A6T). This is the main “carrier” или “pumpkin,” a massive, heavily-ribbed casting made from high-strength ductile iron. This component is the “skeleton” that holds every other part in this list in perfect alignment.

This housing (2402018-A6T) is precision-machined with bores for the main differential bearings (2402049-A6T) and the pinion shaft bearings. These bores are secured by ‘Reducer bearing cap’ (2402024-1ЧАС) and ‘Reducer bearing cap’ (2402019-A6T), which are line-bored as a matched set.

The primary logic of this Логика коробки передач заднего моста FAW в сборе housing is to maintain the **gear mesh**. The alignment between the ring gear and the pinion gear must be perfect, down to a few thousandths of an inch. Any misalignment will cause a “howl” или “whine” and will quickly destroy the gearset. This housing is the zero-tolerance foundation for the entire Логика коробки передач заднего моста FAW в сборе.

The “Reduction” Logic: Ring and Pinion (io=2.867)

The “Reduction Gearbox” part of the Логика коробки передач заднего моста FAW в сборе is the main gear set, specified here as ‘Rear axle reduction gearbox assembly (io=2.867)’ (2402010QA6T and 2403010QA6T). This is the “ring and pinion” set.

The “io=2.867” is the critical “logic” – it is the **Input/Output ratio**. This means that for every 2.867 revolutions of the driveshaft (the pinion gear), the ring gear (and thus the wheels) will rotate exactly *once*. This is the final gear reduction in the entire powertrain, multiplying the torque from the transmission to provide the immense power needed to move a fully-loaded trailer.

The ‘Pinion shaft assembly’ (2402065-A6T) is the “input” механизм, which is connected to the driveshaft. It is supported by a ‘Tapered roller bearing assembly’ (2402050-A8T-C00) and a ‘Cylindrical roller bearing assembly’ (2402075-A6T-C00). This shaft is sealed by the critical ‘Pinion shaft oil seal assembly’ (2402055-A8T-C00), which prevents oil from leaking out the front of the Логика коробки передач заднего моста FAW в сборе.

The “Logic” Сборка: The Differential Lock (2406025-A3C)

The most important “logic” in the Логика коробки передач заднего моста FAW в сборе is the **Differential Lock**. A standard differential (which this assembly also contains) is designed to let the outside wheel spin faster than the inside wheel during a turn. Однако, in low-traction (грязь, ice, gravel), this logic is a weakness, as it will send 100% of the power to the one wheel that is spinning uselessly.

The ‘Fork assembly’ (2406025-A3C) and its ‘Fork’ (2406024AA6T) are the heart of the “diff lock” system. When the driver flips the “diff lock” switch in the cab, a pneumatic ‘Air cylinder’ (2406016-A6T) (powered by air from the ‘Air cylinder inlet bolt’ 2406017-А0Е) moves a shaft. This shaft moves the ‘Fork assembly’, which in turn slides a ‘Sliding gear’ (2406032AA6T) into place.

This sliding gear physically *locks* the differential’s “spider gears,” forcing both axle shafts to rotate at the *exact same speed*. This bypasses the differential action and ensures that both wheels receive equal torque, providing maximum traction. The ‘Return spring-inter wheel differential lock’ (2406028-А0Е) disengages this lock when the air pressure is released. Этот “on-demand” traction logic is what makes the Логика коробки передач заднего моста FAW в сборе so effective.

Precision Shimming: The Adjustment Gaskets

The long-term survival of the Логика коробки передач заднего моста FAW в сборе depends on its “shimming.” The parts list details a large number of ‘Adjustment gaskets’ and ‘Adjustment rings’ (2402088D1HB2, 2402091Д1Х, 2402098-A6T, 2402099-A6T, 2403072-A6T, 2403074-А9Т, 2403073-A6T, 2403070-A6T).

These are not standard gaskets; they are **selective shims**. They are used by a technician to set two critical, non-negotiable tolerances:

1. **Bearing Preload:** The precise “squeeze” on the tapered roller bearings (2402049-A6T, 2402050-A8T-C00). Too loose, and the shaft “walks”; too tight, and the bearing seizes.
2. **Gear Backlash:** The tiny “gap” between the ring and pinion gear teeth. Too much gap, and the teeth “hammer” each other, “clunking” and eventually breaking. Too little gap, and the gears bind, whine, and are destroyed by friction.

A technician must use a dial indicator to measure these tolerances and then select the *exact* combination of these “as needed” (по требованию) shims to build the Логика коробки передач заднего моста FAW в сборе to perfect factory specifications. This shimming logic is the most advanced part of servicing the Логика коробки передач заднего моста FAW в сборе.

FAW Rear Axle Reduction Gearbox Logic Assembly Parts List (1/2)

The following table provides the first part of the detailed breakdown for the Логика коробки передач заднего моста FAW в сборе.

FAW Rear Axle Reduction Gearbox Logic Assembly Parts List (2/2)

This table details the remaining components for the Логика коробки передач заднего моста FAW в сборе.

Technical Specifications and Assembly Context

The specifications for the Логика коробки передач заднего моста FAW в сборе are defined by its dual function as a final-drive reduction gear and a pneumatically-actuated differential lock. The Логика коробки передач заднего моста FAW в сборе is the “logic” of the drive axle.