The part is a state-of-the-art ZF 12-speed automated manual transmission (AMT) specifically engineered for heavy-duty applications, offering exceptional durability, efficiency, and driver comfort for the Sitrak C7H. This advanced transmission delivers superior performance across the full range of operating conditions, from long-haul highway cruising to demanding off-road and construction site operations.
This comprehensive transmission unit, designated as the ZF 12TX2621TD (16.688/430 push/shaft 116.5/T3/encryption 1), is a complete replacement solution for the Sitrak C7H. Every component of The part is engineered to the highest OEM standards, ensuring a perfect fit and reliable performance under the most demanding conditions.
The part features a total ratio spread of 16.688, providing optimal gear selection for both low-speed maneuverability and high-speed fuel efficiency. With a 430mm push-type clutch interface and a 116.5mm input shaft, this transmission is designed to handle the full torque output of the C7H engine. The T3 designation indicates the latest generation of control software, offering predictive shifting and enhanced drivability. This 12TX2621TD transmission is built with precision-forged gears and heavy-duty bearings to ensure long service life and minimal maintenance requirements.
For complete technical specifications and ordering details, please refer to the official Sinotruk Catalog, which provides comprehensive information on all available variants and compatible truck models for The part.
Whether you are replacing a worn transmission or upgrading to the latest ZF AMT technology, The part delivers unparalleled performance, fuel economy, and driver comfort. This 12TX2621TD transmission is the definitive choice for operators who demand reliability, efficiency, and advanced control features in their heavy-duty truck.
The part is a fully integrated 12-speed automated manual transmission that combines the efficiency of a manual gearbox with the convenience of automatic shifting. Its 16.688 ratio spread ensures that the engine always operates at its most efficient rpm, whether climbing steep grades or cruising at highway speeds.
The transmission features a 430mm push-type clutch interface, allowing direct connection to the C7H’s diaphragm spring clutch. The 116.5mm input shaft diameter provides exceptional torsional strength and durability, capable of handling engine torque outputs up to 2,600 Nm. The T3 designation indicates the third-generation control logic, which includes adaptive learning algorithms that adjust shift points based on driving style, load, and terrain.
The encryption 1 feature ensures secure communication between the transmission control unit and the vehicle’s CAN bus system, protecting against unauthorized modifications and ensuring compliance with emissions regulations. This 12TX2621TD transmission is built with case-hardened gears, triple-cone synchronizers for smooth shifting, and an integrated oil-cooler for consistent performance in extreme temperatures. Its lightweight aluminum housing reduces overall vehicle weight, contributing to improved fuel economy and payload capacity.
The part also includes an optional integrated retarder (depending on configuration), providing additional braking power for hilly terrain and reducing wear on the service brakes. Its maintenance-free clutch actuation system and extended oil-change intervals (up to 300,000 km) minimize operating costs and downtime, making The part a highly cost-effective solution for fleet operators.
The part is a product of ZF’s decades of experience in commercial vehicle transmissions, renowned for their durability, smooth operation, and low maintenance requirements. This transmission has been rigorously tested in the harshest conditions worldwide, ensuring it delivers consistent performance in your Sitrak C7H.
With a total ratio spread of 16.688, The part ensures that the engine operates in its sweet spot across all driving conditions. This results in improved fuel economy, reduced engine wear, and quieter operation, making it an ideal choice for long-haul fleet operators.
The T3 control software of The part uses GPS and topographic data to predict upcoming terrain, automatically selecting the optimal gear for hills, descents, and curves. This feature reduces fuel consumption by up to 5% and enhances driver safety by maintaining consistent speeds.
The 12TX2621TD is manufactured to the exact specifications of the original equipment, guaranteeing a perfect fit on the Sitrak C7H without the need for adapters or modifications. The transmission is delivered as a complete unit, ready for installation, and includes all necessary mounting brackets and electrical connectors.
Our online catalog provides comprehensive access to genuine SINOTRUK parts for all major vehicle lines — including HOWO, Sitrak, Steyr, and Yellow River series trucks. You can browse detailed specifications, original part numbers, and exploded-view diagrams for every assembly. Whether you are performing routine maintenance or planning a major overhaul, the catalog helps you quickly identify the correct components for your vehicle. When you become a SINOTRUK customer, we offer complimentary full‑access catalog services, ensuring you always have the latest product data and interchangeability information at your fingertips to support efficient fleet management and accurate parts ordering.
We are a heavy-duty truck parts store. Please leave your contact information and inquiries. We will respond within 12 hours.
