Product Introduction

This heavy-duty middle shell is the main structural housing for the transmission’s core components, engineered to withstand the high torque and vibration of heavy-duty commercial vehicle operations.

• Structure & Material: Made from high-strength cast iron, it features precision-machined internal surfaces for bearing and shaft alignment, external mounting points for auxiliary components, and sealing surfaces to retain gear oil.

• Performance: The rigid cast iron construction ensures exceptional structural integrity, while precision-machined surfaces guarantee accurate alignment of the gear train and leak-free sealing.

• Durability: The robust cast iron resists deformation, cracking, and wear, providing a long service life even under extreme loads and harsh operating conditions.

• Compatibility: Direct OE replacement, fully matching the mounting points and dimensional specifications of the HW19710 transmission.

Core Function

1. Structural Support: Provides the main housing for the transmission’s gear train, shafts, and synchronizers, ensuring precise alignment and stability.

2. Component Mounting: Offers secure mounting points for shift forks, bearings, and other internal components, as well as external sensors and actuators.

3. Sealing & Protection: Encloses the transmission’s internal components, protecting them from dirt and debris while retaining gear oil for lubrication and cooling.

Transmission Middle Shell AZ2220010102 – SINOTRUK HW Series Gearbox Replacement Part

When your fleet relies on SINOTRUK heavy-duty trucks, every gearbox component matters. The Transmission Middle Shell AZ2220010102 is a critical structural housing designed specifically for the SINOTRUK HW Series Gearbox. It serves as the backbone that holds internal transmission assemblies in precise alignment, ensuring smooth gear engagement and long-term drivetrain reliability. Whether you are restocking your warehouse or fulfilling urgent customer orders, Mettlead delivers this genuine-spec part at competitive factory-direct prices — so you can protect your margins while keeping your clients’ trucks on the road.

Key Features and Business Benefits of the Transmission Middle Shell AZ2220010102

This transmission middle shell is far more than a simple casting. It is an engineered housing that plays a vital role in the overall performance and durability of the HW series gearbox. Here is what makes it stand out — and why it makes sense for your bottom line:

• Precision-Machined Casting: Manufactured to meet OEM dimensional tolerances, the AZ2220010102 middle shell ensures all internal shafts, bearings, and gear clusters seat correctly. This eliminates premature wear caused by misalignment.
• High-Strength Alloy Material: Built from durable aluminum-alloy or cast-iron composite (matching OE specification), the housing withstands extreme torque loads and thermal cycling typical in heavy-haul applications.
• Optimized Lubrication Channels: Integrated oil passages within the shell ensure adequate lubrication reaches every gear mesh point, reducing friction-related failures across extended service intervals.
• Direct Bolt-On Fitment: Designed as a drop-in replacement, this middle shell matches the original mounting pattern, gasket surfaces, and dowel-pin locations. Your customers won’t need any aftermarket modifications.
• Wholesale-Friendly Pricing: Because Mettlead sources directly from certified factories in China, you get access to bulk pricing without sacrificing quality — ideal for distributors and workshop chains managing tight procurement budgets.
• Fast Inventory Turnover: High demand for SINOTRUK HW gearbox parts across Africa, Southeast Asia, the Middle East, and South America means this SKU moves quickly. Stocking it builds customer loyalty and repeat orders.

Technical Specifications – Transmission Middle Shell AZ2220010102

Accurate product parameters matter when you are matching parts to customer applications. The table below summarizes the essential specs for the SINOTRUK HW Series Gearbox Transmission Middle Shell AZ2220010102:

Application Scenarios – Where Does the AZ2220010102 Transmission Middle Shell Fit?

Understanding exactly where this part belongs helps you confidently recommend it to your customers and avoid costly returns. The Transmission Middle Shell AZ2220010102 is engineered for the following applications:

• SINOTRUK HOWO Heavy-Duty Trucks equipped with HW19710 or HW19712 gearboxes — commonly used in long-haul freight, mining haulage, and construction logistics.
• SINOTRUK HOWO A7 Series featuring the HW series transmission for inter-city cargo transport and port container delivery.
• SITRAK C7H / T7H Models using compatible HW gearbox variants in premium heavy-haul configurations.
• Gearbox Overhaul and Rebuild Projects: Workshops replacing cracked, worn, or damaged middle shells during full transmission rebuilds frequently require this part to restore housing integrity.

In short, if the vehicle runs a SINOTRUK HW series gearbox and the middle shell has developed cracks, oil leaks at the gasket surface, or bearing bore wear, the AZ2220010102 is the replacement solution your customers need. You can explore more compatible gearbox components in our Gearbox Parts Collection and our dedicated SINOTRUK HOWO Gearbox Parts page.

OEM / ODM Capability and Custom Packaging

As a wholesale distributor or regional agent, you need a supply partner who adapts to your brand strategy — not the other way around. Mettlead offers flexible OEM and ODM services tailored specifically to the aftermarket truck parts industry:

• White-Label Packaging: Receive the Transmission Middle Shell AZ2220010102 in unbranded, neutral packaging — ready for you to apply your own labels and build brand equity in your local market.
• Custom Brand Packaging: Want your company logo, part number cross-reference, and barcode printed directly on the box? We handle the entire packaging design and printing process in-house.
• Strict Quality Control: Every transmission middle shell undergoes dimensional inspection, pressure testing, and surface-finish verification before shipment. We stand behind what we ship.
• Flexible Order Quantities: Whether you need a trial order of 5 pieces or a container load of 200+, our production lines scale to your demand without compromising lead times.
• Factory Visits Welcome: We encourage serious partners to visit our facilities in China. Seeing the quality control process firsthand builds the confidence you need for a long-term sourcing relationship.

Browse our full range of SINOTRUK HOWO Truck Parts to discover additional product lines that complement this gearbox housing.

Customer Case Study – Transmission Middle Shell AZ2220010102 in Action

Earlier this year, a parts distributor based in East Africa reached out to Mettlead with an urgent requirement. Their largest workshop client was overhauling 12 SINOTRUK HOWO dump trucks that had accumulated over 300,000 km each in mining operations. The gearbox middle shells on several units had developed hairline cracks near the bearing bores, leading to oil seepage and alignment issues during shifts.

After confirming the OEM part number — AZ2220010102 — our team verified stock availability and shipped 15 units of the Transmission Middle Shell for the SINOTRUK HW Series Gearbox within 5 business days. Each piece arrived in custom-branded packaging carrying the distributor’s own logo, ready for direct delivery to the workshop.

The result? All 12 trucks were back in service within two weeks. The workshop reported smooth gear engagement, zero oil leaks at the housing gasket, and full confidence in long-term durability. That single order turned into a recurring quarterly purchase — because when the Transmission Middle Shell AZ2220010102 fits right the first time, customers come back.

Frequently Asked Questions – Transmission Middle Shell AZ2220010102

What exactly does the transmission middle shell do inside the HW gearbox?

Think of the middle shell as the structural spine of the gearbox. It houses the mainshaft, countershaft, and synchronizer assemblies in a precisely bored cavity. Without a dimensionally accurate middle shell, gear alignment suffers, bearing loads become uneven, and premature transmission failure follows. The AZ2220010102 maintains OEM-level tolerances to keep all rotating components in their intended positions.

How do I confirm that AZ2220010102 fits my customer’s truck?

First, verify the gearbox model number stamped on the existing transmission housing — it should be an HW series unit (e.g., HW19710, HW19712, HW15710). Second, cross-reference the original part number on the middle shell itself. If it reads AZ2220010102, you have a direct match. If you are still unsure, send us the VIN or gearbox nameplate photo and our team will confirm fitment within 24 hours.

What are common signs that the transmission middle shell needs replacement?

Several symptoms indicate middle shell failure: persistent oil leakage at the shell mating surface despite new gaskets, unusual bearing noise during gear engagement, difficulty shifting between ranges, or visible cracks on the exterior casting. In heavy-duty applications like mining and construction, vibration-induced fatigue cracking is the most frequent failure mode.

Is the AZ2220010102 middle shell supplied as a bare housing or with internal components?

This part is supplied as the bare middle shell casting — precision machined and ready for assembly. Bearings, shafts, gears, and gaskets are ordered separately. This approach gives workshops flexibility to reuse serviceable internals while replacing only the compromised housing.

What quality checks does Mettlead perform on this transmission middle shell before shipping?

Every AZ2220010102 unit passes through a multi-point inspection: CNC bore diameter verification, gasket surface flatness measurement, bolt-hole pattern alignment check, visual crack inspection, and anti-corrosion coating thickness testing. Units that fail any checkpoint are rejected — no exceptions. This ensures you receive only parts that will perform reliably once installed.

Can I order a sample before committing to bulk quantities?

Absolutely. We encourage new partners to start with a sample order so you can physically inspect the casting quality, verify dimensions against OEM specs, and test fitment in your own workshop environment. Once satisfied, scaling to bulk orders is straightforward and comes with improved unit pricing.

Ready to Stock the Transmission Middle Shell AZ2220010102? Let’s Talk.

Your customers depend on you for fast access to quality SINOTRUK HW gearbox parts — and you deserve a supply partner who makes that effortless. Mettlead offers factory-direct pricing, strict quality assurance, flexible packaging options, and reliable global shipping on the Transmission Middle Shell AZ2220010102 and thousands of other Chinese heavy truck components.

Whether you need a competitive quote, want to confirm fitment details, or are ready to place your first bulk order, our team responds within 24 hours.

Contact us now to request wholesale pricing on the Transmission Middle Shell AZ2220010102 for SINOTRUK HW Series Gearbox — and discover why distributors across 30+ countries trust Mettlead as their go-to source for Chinese truck parts.