Product Introduction

• Structure: Precision forged from 20CrMnTi alloy steel, featuring an external involute tooth profile (38 teeth) and internal splines (18 teeth) for engagement with the main shaft. The gear is integrated with a synchronizer friction cone, and the intermediate ring has 6 lightening holes to reduce rotational inertia. The entire gear undergoes full carburizing, quenching, and precision grinding, achieving surface hardness HRC 58–62(anti-pitting/wear) and core hardness HRC 33–45 (anti-impact fracture). The friction cone surface is coated with molybdenum disulfide (MoS₂) for enhanced synchronization performance.

• Performance: The MoS₂-coated friction cone enables rapid speed synchronization (≤0.4s per shift) during 3rd gear engagement, even under 2500N·m torque. The carburized tooth surface resists pitting and wear in long-term cruising scenarios, while the lightening holes reduce rotational inertia to improve shift responsiveness. The precision-ground tooth profile ensures smooth meshing with the countershaft 3rd gear, minimizing noise and vibration.

Core Function

1. 3rd gear power transmission: Transmits torque from the main shaft to the countershaft 3rd gear, providing a medium torque ratio for steady-speed heavy-load cruising (60–80 km/h).

2. Synchronization cooperation: The integrated friction cone works with the 3rd gear synchronizer ring to equalize speeds, enabling smooth shifting under load.

3. Reduced rotational inertia: The lightening holes lower gear inertia, improving shift speed and reducing synchronizer wear.

Main Shaft 3rd Gear AZ2210040225 – SINOTRUK HW Series Gearbox Replacement Part

When your SINOTRUK HW series gearbox demands a reliable replacement, the Main Shaft 3rd Gear AZ2210040225 stands as the precision-engineered solution that keeps your heavy-duty fleet moving. Manufactured to meet OEM specifications, this gearbox gear delivers the exact fitment, material hardness, and tooth profile your transmission system requires. At Mettlead, we supply this genuine-quality component directly from our factory at competitive wholesale pricing — so you can reduce downtime and control procurement costs simultaneously.

Key Features and Benefits of Main Shaft 3rd Gear AZ2210040225

Choosing the right gearbox component is never just about price — it is about performance, longevity, and total cost of ownership. Here is exactly what makes this main shaft 3rd gear a smart procurement decision:

• OEM-Grade Precision: The AZ2210040225 main shaft 3rd gear is manufactured to match original SINOTRUK specifications, ensuring seamless integration with HW series gearbox assemblies without modification.
• Superior Material Composition: Crafted from high-strength alloy steel with carburized and hardened tooth surfaces, this gear resists wear, pitting, and fatigue even under extreme torque loads.
• Optimized Tooth Profile: The precisely ground gear teeth promote smooth power transmission, reduced noise, and minimal vibration throughout the entire operating range.
• Extended Service Life: Thanks to advanced heat treatment processes, this 3rd gear delivers exceptional durability — meaning fewer replacements and lower long-term maintenance costs for your fleet.
• Factory-Direct Pricing: By sourcing directly from Mettlead, you eliminate middlemen and access genuine wholesale pricing without sacrificing quality assurance.
• Strict Quality Control: Every single AZ2210040225 gear undergoes dimensional inspection, hardness testing, and surface finish verification before leaving our facility.

Technical Specifications – Main Shaft 3rd Gear AZ2210040225

Below you will find the precise technical parameters for this SINOTRUK HW series gearbox component. These specifications ensure you can verify fitment and compatibility before placing your order:

Application Scenarios – Where Does AZ2210040225 Fit?

Understanding precisely where and how the Main Shaft 3rd Gear AZ2210040225 functions within the transmission system helps you make a confident purchasing decision. This component is specifically engineered for the following applications:

• Compatible Gearbox Models: SINOTRUK HW series manual transmissions, including HW19710, HW15710, HW19712, and HW20716 gearbox variants.
• Applicable Vehicle Models: SINOTRUK HOWO A7, HOWO T7H, SITRAK C7H, SITRAK C5H, and other heavy-duty trucks equipped with HW series transmissions.
• Function: The main shaft 3rd gear transmits torque from the countershaft to the main shaft when the driver selects third gear, enabling the vehicle to operate at medium-speed cruising conditions with optimal power delivery.
• Replacement Scenarios: Worn tooth surfaces, chipped gear teeth, excessive gear noise in 3rd gear, or difficulty engaging 3rd gear typically signal the need for AZ2210040225 replacement.

Whether you are maintaining a long-haul logistics fleet, managing a construction site with dump trucks, or operating a regional distribution network, this gearbox gear ensures your SINOTRUK vehicles maintain consistent transmission performance. For more SINOTRUK gearbox components, explore our complete gearbox parts category and our dedicated SINOTRUK HOWO gearbox parts collection.

OEM/ODM Capability – Custom Solutions for Your Market

At Mettlead, we understand that different markets have different requirements. That is why we offer flexible manufacturing and branding options for the Main Shaft 3rd Gear AZ2210040225 and our entire gearbox parts range:

• White-Label Packaging: We can supply AZ2210040225 in neutral packaging — perfect if you are building your own aftermarket parts brand in your local market.
• Custom Packaging & Branding: Need your company logo, part number, or specific packaging design? Our team handles custom packaging from small minimum order quantities.
• Bulk Order Flexibility: Whether you need 10 pieces or 10,000 pieces, our production capacity scales to meet your volume requirements without compromising delivery timelines.
• Quality Documentation: We provide material certificates, inspection reports, and detailed product data sheets to support your own quality management processes.
• Factory Visits Welcome: We invite procurement managers to visit our facility in China and inspect our quality control processes firsthand. Transparency builds trust.

Discover our full range of SINOTRUK HOWO truck parts and spare parts to see how we can become your single-source supplier for heavy truck components.

Customer Case Study – Main Shaft 3rd Gear AZ2210040225 in Action

Earlier this year, a fleet management company based in East Africa reached out to Mettlead with an urgent requirement. They were experiencing repeated 3rd gear engagement failures across multiple SINOTRUK HOWO A7 tractor units in their logistics fleet. After inspecting the faulty gearboxes, their technical team confirmed that the main shaft 3rd gear had suffered severe tooth surface pitting due to substandard aftermarket replacements sourced previously.

Our engineering team recommended the genuine-quality Main Shaft 3rd Gear AZ2210040225 as a direct OEM-equivalent replacement for their HW19710 gearbox assemblies. We shipped an initial order of 50 units with full quality inspection documentation. Within two weeks of installation, the customer reported smooth 3rd gear engagement across all repaired vehicles, with no abnormal noise or vibration.

Three months later, that same customer placed a repeat order — this time for 200 units of AZ2210040225 along with additional SINOTRUK HW series gearbox spares. The result? Their fleet downtime dropped by over 40%, and they consolidated their gearbox parts sourcing entirely through Mettlead. Today, they consider us their primary supplier for all SINOTRUK gearbox parts, and we continue to support their growing fleet operations across the region.

Frequently Asked Questions – Main Shaft 3rd Gear AZ2210040225

What gearbox models does the AZ2210040225 main shaft 3rd gear fit?

The Main Shaft 3rd Gear AZ2210040225 is designed specifically for the SINOTRUK HW series gearbox family. This includes popular models such as HW19710, HW15710, HW19712, and HW20716 transmissions commonly found in HOWO A7, HOWO T7H, SITRAK C7H, and other heavy-duty SINOTRUK vehicles.

Is this AZ2210040225 gear an original OEM part or an aftermarket replacement?

This main shaft 3rd gear is manufactured to OEM-equivalent specifications. It matches the original SINOTRUK dimensions, material grade, heat treatment, and tooth profile precisely. While it is produced as an aftermarket component, it delivers the same performance and fitment as the factory-installed part.

What material is the Main Shaft 3rd Gear AZ2210040225 made from?

The AZ2210040225 is forged from high-strength alloy steel. It undergoes a carburizing, quenching, and tempering heat treatment process that achieves a tooth surface hardness of HRC 58–62. This ensures excellent wear resistance and fatigue strength under heavy torque loads typical in commercial truck transmissions.

How can I verify that AZ2210040225 is the correct part number for my gearbox?

You can verify the part number by checking your existing gearbox maintenance manual or by locating the original gear and reading the stamped part code. Alternatively, provide us with your gearbox model number (for example, HW19710) and VIN, and our technical team will confirm compatibility for you.

What causes the main shaft 3rd gear to wear out or fail?

Common failure causes include insufficient lubrication, contaminated gearbox oil, overloading beyond rated torque capacity, aggressive shifting habits, and natural wear over high-mileage operation. Using low-quality aftermarket gears with improper heat treatment can also accelerate tooth surface pitting and premature failure.

What is the minimum order quantity for AZ2210040225?

Mettlead supports flexible order quantities. Whether you need a single piece for an urgent repair or hundreds of units for inventory stocking, we accommodate your needs. Bulk orders benefit from additional volume-based pricing advantages.

Can I get custom or white-label packaging for this gearbox gear?

Absolutely. We offer neutral packaging as standard, and we also support fully customized packaging with your own brand name, logo, and part number printed on the box. This is ideal for distributors building their own aftermarket parts brand.

Ready to Source Main Shaft 3rd Gear AZ2210040225? Get Your Quote Today

Stop wasting time and money on unreliable gearbox parts. When you partner with Mettlead for the Main Shaft 3rd Gear AZ2210040225, you gain access to factory-direct pricing, verified quality, and a dedicated support team that understands SINOTRUK HW series transmissions inside and out.

Here is what happens when you reach out:

1. Submit Your Inquiry: Tell us the part number (AZ2210040225), quantity, and any packaging requirements.
2. Receive a Competitive Quote: Our team responds within 24 hours with pricing, lead time, and shipping options tailored to your location.
3. Confirm and Ship: Once confirmed, your order enters production or ships from ready stock — fast, secure, and fully inspected.

Take the next step and contact us now to request your personalized quotation. Our team is ready to support your procurement needs for SINOTRUK gearbox parts and beyond.