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Brand: C.OEFT
OE numbers: 121000000AA
Product Name: Automatic Transmission Assembly
Compatible model:121000000AA
Product status:Remanufactured
Product weight: 100.000KG
Packaging size:100X100X100 cm
Product packaging: Neutral Packaging
Car Series: Chinese
Car Type: for Chery Tiggo 8 T18 and Chery Tiggo 8
1. Basic Power Transmission & Torque Adjustment
As the core drivetrain component for compact vehicles, the assembly transfers power from the 1.2L-1.6L engine to the drive wheels via an integrated torque converter. The torque converter uses hydraulic fluid to transmit power, providing torque multiplication (2-2.5x) during low-speed acceleration to ensure sufficient 起步动力. The internal gear sets adjust torque and speed according to driving conditions, enabling the vehicle to adapt to urban stop-and-go traffic and highway cruising.
2. Automatic Gear Shifting for Daily Commuting
Working in conjunction with the vehicle’s TCU, the assembly 实现 fully automatic gear changes without driver intervention. The TCU monitors basic vehicle parameters such as engine RPM, throttle position, and vehicle speed to determine optimal shift points. For example, during gentle acceleration (throttle opening ≤30%), it upshifts early to save fuel; during moderate acceleration (throttle opening 30-60%), it maintains gears to balance power and efficiency—perfectly suited for daily commuting needs.
3. Standard Torque Converter Operation
The torque converter consists of three basic components: impeller (engine-driven), turbine (transmission-driven), and stator (torque multiplier). During low-speed operation (e.g., starting from a stop), the stator redirects fluid flow to multiply torque, ensuring smooth 起步 without stalling. At speeds above 60 km/h, the TCU activates the lockup clutch to mechanically link the impeller and turbine, eliminating fluid slippage and improving power transfer efficiency by 4-6%.
4. Basic Hydraulic System Regulation
The valve body serves as the assembly’s hydraulic control center, directing transmission fluid to clutch packs, solenoids, and the torque converter via standard passages. A simple pressure regulator maintains hydraulic pressure within 0.5-2.0 bar, ensuring consistent clutch engagement. A basic pressure relief valve prevents overpressure damage, while a standard filter traps debris to protect internal components from contamination.
5. Basic TCU Communication & Diagnostics
The assembly connects to the TCU via a 12-pin electrical connector, transmitting essential data such as transmission fluid temperature (monitored by a basic NTC sensor) and gear position. If a fault is detected (e.g., solenoid failure, low fluid pressure), the TCU stores a diagnostic trouble code (DTC) such as P0700 (transmission control system malfunction) and illuminates the transmission warning light. Mechanics can retrieve codes using universal diagnostic tools (e.g., Launch X431) for simple troubleshooting.
6. Essential Safety Features
Park (P) Position: Engages a basic mechanical parking pawl that locks the output shaft, preventing the vehicle from rolling when stationary.
Reverse (R) Interlock: Requires the brake pedal to be pressed before shifting from P/N to R, preventing accidental reverse engagement.
Basic Limp-Home Mode: If a critical fault is detected, the TCU limits the assembly to 2nd gear, allowing the driver to safely reach a repair facility without further damage.
1. Broad OE-Grade Compatibility for Compact Vehicles
The Transmission Assembly Gearbox 121000000AA is engineered with universal adaptability, primarily targeting compact passenger cars equipped with 1.2L-1.6L naturally aspirated engines, including popular models from domestic brands like Chery, Changan, and Great Wall. It adheres to industry-wide OE design benchmarks, matching standard parameters such as bell housing bolt patterns (6-bolt configuration), input/output shaft spline specifications (18-spline input, 24-spline output), and mounting hole positions with a tolerance of ±0.15mm. This wide compatibility eliminates the need for custom modifications, enabling mechanics to use it across multiple compact vehicle platforms while avoiding common issues like powertrain misalignment or TCU (Transmission Control Unit) communication errors.
2. Durable Basic Construction for Daily Use
Gear System: Core gear sets are crafted from 20CrMnTi alloy steel, processed through carburizing, quenching, and precision grinding to achieve a surface hardness of HRC 56-60 and core toughness of ≥85 J/cm². This allows the assembly to withstand continuous torque loads of up to 180 Nm, perfectly matching the power output of 1.2L-1.6L naturally aspirated engines for daily commuting.
Housing: Die-cast from ADC10 aluminum alloy with basic reinforcing ribs at stress points, the housing resists vibration (up to 30g) and thermal expansion, maintaining structural integrity in operating temperatures ranging from -35°C to 120°C—suitable for most urban and suburban driving environments.
Sealing & Protection: Equipped with double-lip nitrile rubber seals and galvanized steel gaskets, the assembly provides reliable protection against transmission fluid leakage. A simple dust cover on the input shaft prevents large debris from entering, ensuring basic durability for daily use.
3. Stable Shift Performance & Fuel Efficiency
Featuring a standard-calibrated valve body and reliable solenoids (response time ≤300ms), the 121000000AA delivers smooth and consistent gear transitions, avoiding the shudder or lag common in aging transmissions. Its 4-speed automatic configuration (gear ratios: 1st 3.050, 2nd 1.750, 3rd 1.000, 4th 0.750) is optimized for compact vehicle dynamics—lower gears provide sufficient torque for urban acceleration, while the 4th overdrive gear reduces engine RPM by 10-15% at 100 km/h, improving fuel economy by 5-7% compared to worn original transmissions.
4. Cost-Effective Entry-Level Solution
Priced 40-50% lower than brand-specific OEM assemblies and 15-20% lower than upgraded universal models, the 121000000AA is an economical choice for budget-conscious vehicle owners, repair shops, and fleet operators managing compact cars. Its simplified modular design allows easy replacement of key wear parts (solenoids, clutch packs) without full disassembly, cutting maintenance labor costs. It is compatible with common low-viscosity transmission fluids (ATF 3309), eliminating the need for specialized fluid purchases.
5. Rigorous Basic Quality Testing
Each assembly undergoes an 8-stage quality verification process focused on reliability for daily use: static dimensional inspection, component hardness testing, hydraulic pressure leak testing (1.2x operating pressure), dynamic shift simulation (3,000+ cycles), noise level measurement (≤78 dB at idle), temperature endurance testing (120°C for 3 hours), vibration resistance testing, and final visual inspection. This ensures a failure rate of less than 1% within the first 40,000 kilometers, meeting the basic reliability needs of daily commuting.
6. Easy Installation & Maintenance
Designed with simplicity in mind, the assembly features a standard electrical connector (12-pin) and straightforward mounting points, requiring only basic automotive tools for installation—no specialized equipment needed. Maintenance is simplified, with a readily accessible transmission fluid dipstick and filter, allowing regular fluid changes and filter replacements to extend service life.
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