Un guide vital: Ensemble d'engrenages de distribution FAW pour tracteur CA4251P66K24T1A3E5

Welcome to this vital technical guide on the Ensemble de pignon de distribution FAW, la mécanique “horlogerie” that synchronizes the entire engine of the FAW Jiefang CA4251P66K24T1A3E5 6×4 tracteur semi-remorque diesel. This system is the non-negotiable heart of engine timing.

Unlike a timing belt or chain, le Ensemble de pignon de distribution FAW est un robuste, gear-driven system designed for the extreme torque and high-mileage demands of heavy-duty diesel operation. This assembly connects the crankshaft to the camshaft, pompe d'injection de carburant, et compresseur d'air, ensuring every component operates in perfect, permanent synchronization. Un échec dans le Ensemble de pignon de distribution FAW est catastrophique.

This in-depth guide is an essential resource for professional engine technicians, ateliers d'usinage, et gestionnaires de pièces de flotte. Nous déconstruirons l'ensemble Ensemble de pignon de distribution FAW dans ses plus petites unités utilisables, including every master gear, pignon fou, arbre, and thrust plate, to ensure precision diagnostics and assembly.

The Master and Driven Gears of the Assembly

L'ensemble Ensemble de pignon de distribution FAW operates on a master-and-slave principle. The ‘Crankshaft timing gear’ (1005037-81D) est le “maître” engrenage. It is keyed directly to the snout of the crankshaft and is the single source of power for the entire system. Its rotation is the baseline “time” pour le moteur.

This master gear directly or indirectly drives all other components in the Ensemble de pignon de distribution FAW. Le plus critique “slave” gear is the ‘Camshaft timing gear’ (1006021-81D). This gear is bolted to the front of the camshaft using the ‘Fastening bolt – pignon de distribution d'arbre à cames’ (1006017-53D). It is precisely timed to the crank gear (via idler gears) to ensure the engine’s valves open and close at the correct piston position.

Equally important are the “accessory” drive gears. The ‘Fuel injection pump drive gear’ (1111216-81D) is timed just as precisely, as it drives the high-pressure fuel pump, dictating the exact moment of fuel injection. The ‘Air compressor driven gear’ (1006047-81D) is also driven by this Ensemble de pignon de distribution FAW, providing constant power to the vehicle’s air brake system.

The Idler Gear Train: Transferring Motion

The crank gear and cam gear do not mesh directly; they are too far apart. The space between them is bridged by a series of idler gears. C'est le “logique” dans le Ensemble de pignon de distribution FAW. These idlers are not just spacers; they are precision-engineered components that ensure the correct rotational direction and gear reduction.

This engine uses a “gear train” of multiple idlers. The parts list calls out several ‘Timing idler gear assembly’ unités (1006060-81D and 1006070-81D) and a ‘Timing idler gear (II)’ (1006053-81D). This indicates a multi-gear system to transfer power. One of the most complex is the ‘Timing idler stack-gear assembly’ (1006040-81D). UN “stack-gear” is two gears of different diameters machined onto a single hub. This is a common way to provide two different gear reductions or to offset the rotational path from a single shaft.

Each of these gears must spin freely and in a precise location. They are mounted on dedicated ‘Timing idler gear shafts’. The list specifies a ‘Timing idler stack-gear shaft (je)’ (1006051-81D) and a ‘Timing idler gear shaft (III)’ (1006057-81D). These hardened steel shafts are bolted to the engine block, and the idler gears spin on them, typically on a bronze bushing or needle-roller bearing. The proper lubrication and alignment of this idler train are essential for a quiet and reliable Ensemble de pignon de distribution FAW. Any wear in these bushings will cause a “cliquetis” noise and can lead to gear failure. This entire network of idlers is a core strength of the Ensemble de pignon de distribution FAW.

The axial (front-to-back) position of these helical-cut gears is just as important as their rotation. Helical gears naturally create a “poussée” forcer. Le « Pignon fou de distribution (III) assiette de poussée’ (1006056-81D) is a critical wear item. This hardened steel plate bolts to the front of the idler shaft and provides a low-friction surface for the gear hub to ride against. It prevents the gear from “marche” off its shaft. A worn thrust plate will allow excessive “fin de jeu” in the idler gear, leading to a loud whining noise and potential damage to the entire Ensemble de pignon de distribution FAW.

Critical Fasteners and Locators

A gear-driven system like the Ensemble de pignon de distribution FAW is held together by high-strength, specialized fasteners. The ‘Fastening bolt – pignon de distribution d'arbre à cames’ (1006017-53D) est un célibataire, grand, high-tensile bolt. It is almost certainly a Torque-to-Yield (ATS) bolt that must be replaced after one use. It provides the immense clamping force needed to lock the cam gear to the camshaft, preventing any slippage that would destroy the engine’s timing. This is one of the most critical bolts in the entire Ensemble de pignon de distribution FAW.

The idler gear shafts are secured by various ‘Inner hex socket head cap screws’ (CQ2181040TF2 et CQ2181070TF2) and ‘Hex flange bolts’ (Q1840840). The use of inner-hex (Allen key) bolts is common where clearance is tight. These TF2-suffixed bolts are likely high-strength (Classe 10.9 ou 12.9) and may have a factory-applied thread-locking compound. The proper torque on these fasteners prevents the idler shafts from vibrating loose, which would be catastrophic for the Ensemble de pignon de distribution FAW.

Enfin, the ‘Dowel pin’ (Q5210616) provides precision. This hardened steel pin is pressed into the engine block and is used to locate one of the idler gear shafts in its one, exact position. This ensures the gear-to-gear “contrecoup” (the small gap between the teeth) is perfect. Too much backlash causes a rattling noise, while too little (un “serré” engrener) causes a high-pitched whine and rapid wear. This pin ensures the factory-set precision of the Ensemble de pignon de distribution FAW every time it is serviced.

FAW Timing Gear Assembly Parts List

Le tableau suivant fournit l'intégralité, detailed breakdown of all components identified in the ‘Timing Gear Logic Assembly’ schéma du tracteur FAW CA4251P66K24T1A3E5. A complete overhaul of the Ensemble de pignon de distribution FAW requires meticulous inspection of each of these parts.

Spécifications techniques et contexte d'assemblage

Les spécifications pour le Ensemble de pignon de distribution FAW are defined by its function as the master timing system for the engine. L'ensemble Ensemble de pignon de distribution FAW est un appareil de haute précision, heavy-duty system.