AZ221004000008 (040204) Fourth gear

AZ221004000008 (040204) Fourth gear

The AZ221004000008 (040204) four-speed gearbox is adapted to heavy-duty truck gearboxes. It adopts high-strength alloy steel forging + carburizing and quenching + precision grinding process, with high tooth surface hardness, strong wear resistance, excellent impact resistance and fatigue resistance, effectively avoiding problems such as tooth loss, abnormal noise, and uneven wear. It is highly compatible with synchronizers and shaft accessories, making it the preferred accessory for heavy-duty truck gearboxes.

AZ221004000008 (040204) 4th gear is a key transmission component in heavy-duty truck gearboxes, specifically designed for power transmission and conversion in fourth gear. It ensures smooth operation, stable performance, and efficient power delivery during medium to high-speed driving conditions.

Engineered with precision and durability in mind, this gear effectively solves common issues such as gear noise, gear sticking, tooth breakage, and inefficient transmission, making it a reliable choice for heavy truck applications.

Key Features

High Strength Material

Manufactured from premium alloy structural steel through precision forging, providing excellent toughness and strength to withstand high torque and continuous operation.

Advanced Heat Treatment

Carburizing and quenching process ensures:

  • Uniform surface hardness
  • Excellent wear resistance
  • Enhanced fatigue strength

Precision Gear Machining

Gear teeth are finely ground and polished for:

  • High tooth profile accuracy
  • Smooth surface finish
  • Stable and seamless meshing

Optimized Performance

  • Reduced transmission loss
  • Lower noise and vibration
  • Improved driving comfort

Core Functions

Efficient Power Transmission

Ensures stable and precise power delivery in fourth gear, supporting smooth medium- and high-speed driving while balancing performance and fuel efficiency.

Stable & Reliable Operation

Tight gear meshing and high precision design prevent:

  • Gear sticking
  • Abnormal noise
  • Gear jumping
  • Tooth breakage

Product Advantages

  • High durability for long-term heavy-duty use
  • Resistant to deformation and tooth damage
  • Smooth shifting with reduced impact
  • Lower maintenance frequency and downtime
  • Cost-effective solution for gearbox repair
  • Accurate fitment and wide compatibility
  • Ready stock for fast delivery

Technical Specifications

  • Product Name: 4th Gear
  • Model: AZ221004000008 (040204)
  • Application: Heavy Truck Gearbox
  • Material: Alloy Structural Steel
  • Process: Precision Forging + Carburizing & Quenching
  • Surface Treatment: Gear Grinding & Polishing

Application Scenarios

  • Heavy truck gearbox repair and maintenance
  • Transmission system replacement
  • Auto parts wholesalers and distributors
  • Export and OEM supply

Supply & Service

  • Stable inventory for quick shipment
  • Support bulk orders and customization
  • Professional export packaging
  • Technical support and after-sales service

AZ221004000008 (040204) 4th gear is engineered for reliable performance in demanding heavy truck applications. With high-strength materials, precision machining, and optimized transmission efficiency, it ensures smooth operation, reduced noise, and extended gearbox lifespan—making it an ideal choice for repair and replacement needs.

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