Product Introduction

This sun gear is a precision-machined component, manufactured from high-strength alloy steel through a process of precision forging, carburizing heat treatment, and multi-stage grinding. It features external spur gear teeth for meshing with the planetary pinions and internal splines for connection to the axle shaft. The gear undergoes strict quality control, including dimensional inspection and surface hardness testing, to meet OE specifications for heavy-duty operation. Its optimized tooth profile and precision machining ensure smooth meshing, minimal noise, and maximum power transmission efficiency.

Core Function

• Meshes with the planetary pinions in the wheel-end planetary reduction assembly, acting as the central input gear to transfer torque and enable the planetary reduction mechanism.

• Works in conjunction with the planetary pinions and ring gear to achieve the final stage of speed reduction and torque increase, delivering the required low-speed, high-torque output to the wheel hub.

• Maintains precise alignment within the planetary gear set, ensuring smooth and efficient power transmission and minimizing wear on the gear set.

• Withstands the high torque loads and dynamic stresses generated during heavy-duty operation, providing reliable performance and extended service life.

• Directly interchangeable with the original factory part, ensuring a precise fit and consistent performance within the wheel-end planetary reduction assembly.

Sun Gear Z=23 199012340005 Sinotruk – OEM Planetary Transmission Sun Gear

When your Sinotruk heavy-duty truck demands reliable power transfer through its planetary gear mechanism, every single tooth counts. The Sun Gear Z=23 199012340005 sits at the heart of the planetary transmission assembly, meshing precisely with planet gears to distribute torque smoothly and efficiently. Engineered to OEM specifications, this sun gear keeps your drivetrain running the way it was designed to — without compromise.

At Mettlead, we supply this genuine-spec sun gear directly from our factory in China, giving fleet operators, workshop managers, and procurement professionals access to competitive pricing without sacrificing the quality your vehicles depend on.

Key Features and Benefits of Sun Gear 199012340005

Precision-Engineered for Demanding Applications

This sun gear features 23 precisely cut teeth (Z=23) that are designed to engage flawlessly with the surrounding planet gears inside the planetary gear set. As a result, power flows from the input shaft through the gear assembly with minimal energy loss and reduced vibration.

• OEM Part Number: 199012340005 — ensures direct fitment and eliminates guesswork during installation.
• Tooth Count (Z=23): Matched to the factory gear ratio for correct speed reduction and torque multiplication.
• High-Grade Alloy Steel Construction: Heat-treated for superior surface hardness and core toughness, which means this gear resists pitting, wear, and fatigue even under heavy loads.
• Precision Ground Tooth Profile: Delivers smooth meshing, quieter operation, and extended service life across thousands of operating hours.
• Direct Factory Supply: Because we cut out the middlemen, you get OEM-equivalent quality at a more accessible price point.

Why This Matters for Your Fleet

A worn or damaged sun gear doesn’t just create noise — it compromises the entire planetary gear set. Uneven load distribution accelerates wear on planet gears and the ring gear, eventually leading to costly transmission failure. By replacing with a correctly specified part like the 199012340005, you protect the entire assembly and avoid unplanned downtime.

Application Scenarios

Compatible Vehicles and Working Conditions

This sun gear is specifically designed for Sinotruk heavy-duty vehicles equipped with planetary transmission mechanisms in the rear axle assembly. It performs a critical role in the following scenarios:

• Planetary Gear Mechanism: Functions as the central driving gear that transmits input torque to the surrounding planet gears.
• Power Transmission: Transfers engine power through the drivetrain efficiently, maintaining the designed gear ratio under load.
• Speed Variation and Torque Multiplication: Works in coordination with the gear set to achieve the required speed reduction and torque output at the wheel ends.
• Heavy-Load Hauling: Built to withstand the continuous high-torque demands of long-haul freight, mining transport, and construction logistics.

Whether your trucks operate on highways or rough terrain, this sun gear is built to handle the stress that comes with moving serious weight over serious distances.

Technical Specifications

OEM and ODM Capabilities

Flexible Solutions for Your Business

We understand that different markets have different requirements. That’s why Mettlead offers more than just off-the-shelf parts:

• White-Label Packaging: Need to sell under your own brand? We provide neutral or custom-branded packaging tailored to your specifications.
• Custom Packaging Design: From individual part boxes to bulk pallet configurations, we adapt packaging to suit your logistics and retail needs.
• Strict Quality Control: Every sun gear undergoes dimensional inspection, hardness testing, and surface finish verification before it leaves our facility.
• Bulk Order Support: Whether you need 10 pieces or 10,000, our production capacity scales to meet your demand with consistent lead times.

Additionally, if you’re sourcing multiple Sinotruk drivetrain components, we can consolidate shipments to reduce your freight costs. Explore our full range of Sinotruk HOWO Truck Parts or browse our complete Rear Axle Parts catalog for related components.

Frequently Asked Questions

What does the sun gear do inside a planetary gear set?

The sun gear sits at the center of the planetary gear mechanism. It meshes with the planet gears that orbit around it, transmitting rotational force from the input shaft. In simple terms, it’s the starting point of power distribution within the assembly — without it, torque cannot reach the wheel ends.

How do I confirm that part number 199012340005 fits my vehicle?

This sun gear is manufactured to match OEM part number 199012340005, which is specified for Sinotruk heavy-duty vehicles with planetary rear axle assemblies. To confirm compatibility, cross-reference this number with your vehicle’s parts manual or provide us with your VIN and axle model — our team will verify fitment for you.

What causes a sun gear to fail prematurely?

The most common causes include insufficient lubrication, contaminated gear oil, misalignment during installation, or operating consistently beyond rated load capacity. Over time, these conditions lead to surface pitting, tooth fracture, or excessive wear that throws off the entire gear mesh pattern.

Should I replace other components when installing a new sun gear?

It depends on the condition of the surrounding parts. If the planet gears or ring gear show signs of pitting, scoring, or uneven wear, replacing them together ensures proper meshing and prevents the new sun gear from wearing prematurely. We recommend inspecting all mating surfaces during disassembly.

What is the tooth count Z=23, and why does it matter?

The “Z=23” designation indicates this sun gear has exactly 23 teeth. This number directly determines the gear ratio within the planetary set. Installing a gear with the wrong tooth count would alter the speed and torque output, potentially damaging the transmission. Always match the original specification.

Can I order a sample before committing to a bulk purchase?

Yes. We encourage buyers to order samples for inspection and fitment testing. This way, you can verify dimensions, material quality, and compatibility before scaling up your order. Simply reach out to our team to arrange sample shipping.

Ready to Source Your Sun Gear 199012340005?

Getting the right part at the right price shouldn’t be complicated. At Mettlead, we combine factory-direct pricing with reliable quality control, so you can keep your fleet moving without overpaying for components.

Here’s how to get started:

1. Send us your inquiry with the part number, quantity, and destination.
2. Receive a competitive quotation within 24 hours.
3. Confirm your order and choose from our flexible, secure payment options.
4. Track your shipment with fast, reliable delivery to your door.

Have questions or need help identifying the correct part? Contact us today — our parts specialists are ready to assist you.

You can also explore our comprehensive Sinotruk Truck Parts catalog to find everything you need in one place.