Dongfeng FAST Gearbox Assy parts transmission housing 12JSD160T-1701015-24

As the "structural backbone" of the 12JSD160T gearbox, this transmission housing serves three core functions: supporting internal components, containing gearbox oil, and protecting against external damage. Its structural positioning is critical to the gearbox’s overall performance:

Component Support: The housing features precision-machined bearing bores (12-15 bores, depending on gear count) that secure the gear shafts and bearings, maintaining accurate shaft alignment (radial runout ≤0.05mm) to reduce gear meshing noise and wear.

Oil Containment: The sealed cavity formed by the housing (when combined with the upper cover and end caps) holds up to 12-15L of gearbox oil (API GL-5 standard), ensuring sufficient lubrication and heat dissipation for internal gears and bearings.

External Protection: The robust outer structure shields internal components from external impacts (e.g., road debris, uneven terrain collisions) and environmental contaminants (dust, water), preventing premature component failure.

This multi-functional role makes the housing a critical determinant of the gearbox’s reliability and service life

To withstand heavy-duty operating conditions, the housing uses high-quality materials and advanced manufacturing techniques:

Base Material: Made of high-strength gray cast iron (HT300)—a material chosen for its excellent combination of rigidity (Young’s modulus: 110-130 GPa), wear resistance, and vibration damping properties. HT300 also offers superior casting performance, allowing complex internal structures (e.g., bearing bores, oil channels) to be formed with high precision.

Casting Process: Produced via sand casting with resin-bonded sand (to reduce surface defects) and followed by heat treatment (annealing at 600-650℃) to eliminate internal stress—preventing cracking or deformation under high torque and temperature fluctuations.

Precision Machining: Critical surfaces (bearing bores, flange mating faces, oil seal grooves) are processed via CNC turning and milling, with dimensional tolerance controlled within ±0.03mm and surface roughness (Ra) ≤1.6μm. This ensures tight fits with mating components (e.g., bearings, upper cover) and reliable sealing to prevent oil leakage

The housing’s design is optimized for structural strength and resistance to harsh operating environments:

Reinforced Structure: Key stress points (around bearing bores, input/output flanges, and mounting brackets) are equipped with ribbed reinforcements (rib thickness: 8-12mm) that increase structural rigidity by 25-30%—preventing deformation under the 1600 N·m maximum torque of the 12JSD160T gearbox.

Oil Management Features: The internal cavity includes integrated oil baffles and oil return channels that direct oil flow to high-wear components (e.g., synchronizers, bearings) and prevent oil starvation during low-speed operation. A built-in oil drain plug (M20×1.5 thread) allows easy oil replacement during maintenance.

Environmental Resistance: The outer surface undergoes anti-rust painting (epoxy resin coating, thickness: 60-80μm) that resists corrosion from road salt, water, and engine coolant—extending the housing’s service life in harsh weather conditions (e.g., coastal areas, winter road salt use).

The housing maintains structural integrity across a temperature range of -40℃ to 150℃, adapting to extreme cold and high-temperature gearbox operation

The transmission housing is primarily applied in Dongfeng FAST 12JSD160T-equipped heavy-duty vehicles, including:

Dongfeng long-haul tractor-trailers (operating under continuous high-torque conditions for cross-country transportation);

Heavy-duty cargo trucks used for bulk goods transport (exposed to frequent load changes and rough road conditions);

Specialized vehicles like concrete mixers and mining dump trucks (requiring robust gearbox structures to withstand vibration and impact).

In terms of installation, it offers distinct advantages:

Modular Assembly: The housing’s standardized mounting holes (20-25 M10/M12 threaded holes) and component interfaces allow easy assembly of gears, bearings, and the upper cover—compatible with FAST’s original assembly line processes and aftermarket maintenance procedures.

Direct OEM Replacement: Matches the original housing’s dimensions, weight (≈45-50kg), and functional features—no modifications to the engine or vehicle’s transmission mount are needed. Installation requires lifting the gearbox, removing the old housing, and transferring internal components to the new one, which can be completed with standard tools in 2-3 hours (for professional technicians).

Long-Term Durability: Under normal operating conditions (with regular oil changes), the housing has a service life of over 300,000 km—matching the overall service life of the 12JSD160T gearbox and reducing the need for costly gearbox overhauls