Product Introduction

• Structure: An integrated assembly consisting of a high-strength alloy steel hub, sliding sleeve, copper-based synchronizer ring, and spring-loaded shift blocks. The hub and sleeve feature carburized and hardened teeth (HRC58-62) for wear resistance, while the synchronizer ring uses a friction-enhancing copper alloy with a precision-machined cone surface.

• Performance: The copper ring’s friction cone rapidly equalizes the speed of the target gear and main shaft, eliminating gear clash during shifting. The high-hardness teeth ensure reliable torque transmission, and the spring-loaded blocks maintain precise alignment between the sleeve and hub, ensuring consistent performance even under heavy-duty conditions.

Core Function

1. Speed Synchronization: Uses friction between the synchronizer ring and gear cone to match the rotational speed of the target gear to the main shaft, eliminating gear impact.

2. Smooth Gear Engagement: Enables shock-free meshing of the sliding sleeve and gear teeth, improving shift quality and extending component life.

Torque Transmission: Once synchronized, the sliding sleeve locks onto the gear, transferring torque from the main shaft to the output.

Synchronizer Assembly 12JSDX240T-1701170 Fast Gear – Premium Gearbox Component for Heavy-Duty Trucks

When your transmission demands flawless gear engagement under extreme loads, the Synchronizer Assembly 12JSDX240T-1701170 Fast Gear delivers exactly that. Engineered to meet the rigorous standards of Fast Gear (法士特) transmissions, this synchronizer assembly ensures smooth, reliable shifting across thousands of operating cycles. Whether you’re maintaining a fleet of heavy-duty trucks or sourcing replacement gearbox parts for your workshop, this component is built to keep your vehicles on the road longer—with less downtime and lower maintenance costs.

At Mettlead, we supply this synchronizer assembly directly from certified factories in China, which means you get genuine OEM-equivalent quality at a competitive factory-direct price. As a result, procurement managers around the world trust us to deliver the right part, on time, every time.

Key Features and Benefits of the Synchronizer Assembly 12JSDX240T-1701170

Understanding what makes this Fast Gear synchronizer assembly stand out helps you make a more confident purchasing decision. Here’s why this component consistently outperforms generic alternatives:

• Precision-Machined Synchronizer Rings: Each ring is manufactured to exact tolerances, ensuring consistent friction contact and smooth gear engagement even under heavy torque loads.
• High-Grade Material Composition: The assembly uses wear-resistant alloy steel and brass friction surfaces, which significantly extends service life in demanding operating conditions.
• Perfect OEM Fitment: Designed as a direct replacement for part number 12JSDX240T-1701170, this synchronizer assembly drops right into Fast Gear 12JSDX240T series transmissions without modification.
• Reduced Shift Effort: The optimized cone angle and friction coefficient work together to minimize driver fatigue during long-haul operations.
• Strict Quality Control: Every unit undergoes dimensional inspection, hardness testing, and surface finish verification before leaving our facility.
• Extended Transmission Lifespan: By maintaining proper synchronization, this assembly protects other costly gearbox components—such as gear teeth and shift forks—from premature wear.

In other words, choosing the right synchronizer assembly isn’t just about fixing today’s problem—it’s about preventing tomorrow’s breakdown.

Technical Specifications

Below you’ll find the detailed parameters for the Synchronizer Assembly 12JSDX240T-1701170 Fast Gear. These specifications help you verify compatibility and confirm that this is the exact part your transmission requires.

Application Scenarios – Which Vehicles Does This Synchronizer Assembly Fit?

The Synchronizer Assembly 12JSDX240T-1701170 is specifically designed for Fast Gear 12JSDX240T series transmissions. These gearboxes are widely installed across several major Chinese heavy-duty truck platforms, making this part essential for fleet maintenance operations worldwide.

Commonly compatible vehicle brands and models include:

• SINOTRUK HOWO – Heavy-duty tractor units and dump trucks equipped with Fast Gear 12-speed transmissions
• SINOTRUK SITRAK – Long-haul logistics vehicles using the 12JSDX240T gearbox
• SHACMAN (Shaanxi Auto) – F3000, X3000, and H3000 series with Fast Gear drivetrain configurations
• FAW Jiefang – J6P and J7 heavy trucks fitted with 12-speed synchronized transmissions
• DONGFENG – Tianlong and Kinland series commercial vehicles
• FOTON Auman – Heavy-duty models using compatible Fast Gear gearboxes

If you’re unsure whether this synchronizer assembly fits your specific transmission model, simply share your vehicle VIN or gearbox nameplate details with our team. We’ll confirm compatibility before you place your order.

Explore more Fast Gear transmission components in our Fast Gearbox Parts category, or browse our full Gearbox Components range.

OEM/ODM Capability – Custom Packaging and White-Label Solutions

As a procurement manager, you may need more than just a reliable part—you might need it delivered under your own brand. Mettlead offers flexible OEM and ODM services tailored to the global aftermarket:

• White-Label Packaging: We can supply the Synchronizer Assembly 12JSDX240T-1701170 in neutral or custom-branded packaging, complete with your logo, part number labeling, and barcode requirements.
• Custom Packaging Design: Whether you prefer individual boxes, bulk packaging, or export-ready palletization, we adapt to your logistics needs.
• Consistent Quality Across Orders: Our factory maintains strict batch control, so whether you order 50 or 5,000 units, the quality remains identical.
• Documentation Support: We provide packing lists, commercial invoices, certificates of origin, and any additional export documentation your market requires.

This flexibility allows you to build your own parts brand in your local market while sourcing directly from China at factory-level pricing.

Customer Case Study – Synchronizer Assembly 12JSDX240T-1701170 in Action

A fleet maintenance company based in East Africa was experiencing frequent transmission complaints across their 40-vehicle HOWO truck fleet. After inspecting several units, their technicians identified worn synchronizer assemblies as the root cause of hard shifting and gear grinding—particularly in the 12JSDX240T gearboxes.

They reached out to Mettlead looking for a reliable bulk supply of the Synchronizer Assembly 12JSDX240T-1701170 Fast Gear at a competitive price. Our team provided detailed product specifications, confirmed fitment for their exact transmission variant, and arranged a trial order of 30 units.

After installation, the client reported that shifting smoothness was fully restored, and the parts performed identically to the original factory-installed synchronizers. Subsequently, they placed a recurring quarterly order and expanded their purchasing to include additional Fast Gear gearbox components from our catalog.

This case demonstrates what consistent quality, accurate part matching, and responsive communication can do for your fleet’s uptime—and your bottom line.

Frequently Asked Questions About the Synchronizer Assembly 12JSDX240T-1701170

What exactly does a synchronizer assembly do inside the gearbox?

A synchronizer assembly matches the rotational speed of the gear being selected with the output shaft speed. In simpler terms, it eliminates gear grinding during shifts by bringing both components to the same speed before they mesh. Without a properly functioning synchronizer, drivers experience hard shifting, noise, and accelerated wear on gear teeth.

How do I know if my synchronizer assembly needs replacement?

Common symptoms of a failing Synchronizer Assembly 12JSDX240T-1701170 include difficulty engaging specific gears, grinding or crunching noises during shifts, and increased shift effort. If your drivers report that certain gears feel “sticky” or require double-clutching, the synchronizer rings may be worn beyond their service limit.

Is this synchronizer assembly an OEM original or aftermarket part?

The Synchronizer Assembly 12JSDX240T-1701170 we supply is manufactured to OEM-equivalent specifications. It meets the same dimensional tolerances, material hardness, and surface finish standards as the original Fast Gear factory part. This ensures drop-in fitment and reliable long-term performance.

What is the typical service life of this synchronizer assembly?

Under normal operating conditions, a quality synchronizer assembly lasts between 300,000 and 500,000 kilometers. However, actual lifespan depends on driving habits, load conditions, and whether the transmission oil is changed at recommended intervals. Harsh shifting and overloading can shorten service life considerably.

Can I order a single unit, or is there a minimum order quantity?

We support flexible order quantities. Whether you need a single Synchronizer Assembly 12JSDX240T-1701170 for an urgent repair or several hundred for wholesale distribution, Mettlead accommodates your requirements. Larger volumes naturally benefit from better per-unit pricing.

How should I store the synchronizer assembly before installation?

Store the assembly in its original packaging in a dry, temperature-controlled environment. Avoid exposure to moisture, corrosive chemicals, or direct sunlight. The friction surfaces are precision-finished—handling them with clean gloves during installation helps prevent contamination that could affect initial synchronization performance.

Get a Competitive Quote for the Synchronizer Assembly 12JSDX240T-1701170 Today

Ready to secure reliable, factory-direct pricing on the Synchronizer Assembly 12JSDX240T-1701170 Fast Gear? Whether you need a single piece for verification or a bulk order for distribution, our team responds quickly with accurate quotes, lead times, and shipping options tailored to your location.

Here’s what you can expect when you work with Mettlead:

• Factory-direct pricing with no middlemen
• Fast, reliable international shipping
• Flexible and secure payment methods
• Professional part verification before dispatch
• Visitors welcome at our facility for on-site inspection

Contact us now to request your quote, confirm part compatibility, or discuss custom packaging for the Synchronizer Assembly 12JSDX240T-1701170. Our team is standing by to support your procurement needs.