Assemblage du boîtier intermédiaire FAW: Déconstruire le 22 Composants complets

Welcome to this comprehensive technical deconstruction of the Assemblage du boîtier intermédiaire FAW (Partie no. 1701035-A2V), également connu sous le nom de “mid-case.” This is the central, structural skeleton of the main gearbox for the FAW Jiefang CA4251P66K24T1A3E5 6×4 tracteur semi-remorque diesel.

Le Assemblage du boîtier intermédiaire FAW is arguably the most critical and complex casing in the entire transmission. Its function is to hold the main shaft, arbre intermédiaire, and reverse idler shaft in perfect, parallel alignment, all while containing the transmission’s oil supply and supporting the shift-rail mechanism.

Ce guide détaillé est une ressource essentielle pour les techniciens professionnels de transmission et les spécialistes des pièces.. We will analyze all 22 serviceable components of the Assemblage du boîtier intermédiaire FAW, including the main casing, its lubrication system (bouchons, filtres), the shift-fork bushings, and the critical reverse light switch.

Composant principal: The Middle Housing (1701035-A2V)

The heart of this assembly is the ‘Mid-housing with steel wire sleeve set assy’ (1701035-A2V). This is the main body of the Assemblage du boîtier intermédiaire FAW. C'est un énorme, precision-machined casting, typically made of aluminum to save weight and effectively dissipate heat from the gear oil. Ce composant est le “squelette” that everything else bolts into.

Its most critical features are the internal, alésage de précision “selles” ou “bores.” These are the holes that hold the main bearings for the input shaft, main shaft, and counter-shaft. These bores must be perfectly parallel to each other, as any misalignment would cause the gears to mesh improperly, leading to a catastrophic “gémissement” and rapid gear destruction.

The designation “with steel wire sleeve set assy” is a critical quality feature. It means that the high-stress threaded holes in the soft aluminum casting of the Assemblage du boîtier intermédiaire FAW have been reinforced with “Helicoils” (steel wire inserts). This is vital for the ‘Stud bolts’ (CQ1211640) and the many ‘Hex flange bolts’ (Q1841060, Q1840820) that hold the transmission together, preventing the threads from stripping during service and ensuring a high-torque, durable assembly. This is a core feature of a high-quality Assemblage du boîtier intermédiaire FAW.

The Lubrication & Service System

Le Assemblage du boîtier intermédiaire FAW is designed to hold several gallons of heavy-duty gear oil. This parts list details all the critical service points for this fluid.

**1. Oil Fill/Check:** Le « Bouchon de remplissage d'huile »’ (1701041-A2K) est le “remplir” port, located high on the side of the housing. La transmission est remplie jusqu'à ce que l'huile commence à s'écouler de ce trou, which is how the correct oil level is set.

**2. Oil Drain:** L'ensemble de bouchon de vidange’ (1701765-A2K) est le “vidange” port, located at the lowest point. This plug is typically magnetic, designed to trap any fine metal particles from normal gear wear. Inspecting this plug during an oil change is a critical diagnostic step for the health of the Assemblage du boîtier intermédiaire FAW.

**3. Scellage:** Both plugs are sealed by the ‘Gasket-plug, vidange’ (1701042-A2K), dont il y en a deux. Ce sont “rondelles d'écrasement” and are single-use items that must be replaced to prevent leaks. The ‘Inner hex tapered screw plug’ (Q61901) is used to seal a manufacturing or diagnostic port on the Assemblage du boîtier intermédiaire FAW.

Internal Oil Filtration (1701050-A2K)

A critical, yet simple, composante du Assemblage du boîtier intermédiaire FAW‘s lubrication system is the ‘Filter screen assembly’ (1701050-A2K). C'est le “pickup screen” for the transmission’s internal oil pump. It is located deep inside the housing, submerged in the oil sump.

Its function is to provide a “grossier” filtre, blocking any large debris (Par exemple, chipped gear teeth, metal shavings, or gasket fragments) from being sucked into the high-pressure oil pump. A failure of this screen would allow debris to circulate, destroying the oil pump and subsequently starving the entire gearbox of lubrication.

The ‘Gasket-filter screen assembly’ (1701056-A2K) is the seal for this component. Its integrity is vital, as a failed gasket would allow the pump to suck in unfiltered oil from *around* the screen, defeating its purpose. This is a vital part of the Assemblage du boîtier intermédiaire FAW‘s longevity.

Shift System: Bagues, Épingles, and Switch

Le Assemblage du boîtier intermédiaire FAW provides the foundation for the internal shift components (detailed in Assembly 153). This includes the ‘Bushing-reverse fork shaft’ (1701014-A9P) and the three ‘Bushing-shift fork shaft’ (1701013-A9P) unités. These are the bronze “porter” bushings that are pressed into the aluminum housing. The hardened steel shift rails slide through these bushings, allowing for smooth, low-friction shifting.

The ‘Dowel pin-sub housing’ (1701052-A2V) units are used to perfectly align the Assemblage du boîtier intermédiaire FAW to the rear “sous-boîte” (auxiliaire) logement.

A key electronic component mounted to this Assemblage du boîtier intermédiaire FAW is the ‘Reverse light switch assembly’ (3729100-54W-C00). This is a spring-loaded “plunger” changer. When the driver moves the shifter into the reverse gate, the reverse shift rail (supported by 1701014-A9P) pushes this plunger in, which completes an electrical circuit. This signal turns on the vehicle’s white reversing lights and the audible backup alarm, making it a critical safety component.

FAW Middle Housing Assembly Parts List

Le tableau suivant fournit l'intégralité, ventilation détaillée de tous 22 components identified in the ‘Middle Housing Assembly’ schéma du tracteur FAW CA4251P66K24T1A3E5. Ce Assemblage du boîtier intermédiaire FAW is the core of the main gearbox.

Spécifications techniques et contexte d'assemblage

Les spécifications pour le Assemblage du boîtier intermédiaire FAW sont définis par sa fonction de structure, precision-machined “mid-case” de la transmission. L'ensemble Assemblage du boîtier intermédiaire FAW is a key structural component.