Swing Gearbox Fit for Excavator Hitachi ZX120-3
Swing Gearbox Fit for Excavator Hitachi ZX120-3
Swing gearbox, also known as swing drive, is a gearbox that provides rotational power to the excavator's upper structure for 360-degree rotation. It is an essential component of the excavator's hydraulic system with the following functions:
- Enables the excavator to rotate in a full circle, allowing for maximum efficiency in material handling and excavation;
- Transfers power from the hydraulic pump to the excavator's upper structure;
- Provides braking force to stop the upper structure's rotation;
- Reduces the speed of the upper structure??s rotation, allowing for more precise and controlled movements;
- Distributes power to other excavator attachments that require hydraulic power.
Swing Gearbox Installation and Operation
The swing gearbox is located at the excavator??s upper structure and is responsible for turning the excavator's house. When the operator moves the joystick, the hydraulic pump sends oil to the swing gearbox, causing the house to rotate. The gearbox operates on the principle of a planetary gear system, which consists of a central sun gear, planet gears, and an outer ring gear.
Swing Gearbox Fit for Excavator Hitachi ZX120-3
Our Swing Gearbox is specially designed to fit Excavator Hitachi ZX120-3 model. Before purchasing, please confirm the following parameters:
| Parameter | Description |
|---|---|
| Model Number | Hitachi ZX120-3 |
| Swing Ratio | 5.5:1 |
| Output Torque | 3626 N.m |
When to Replace the Swing Gearbox
The following are signs that the excavator's swing gearbox needs to be replaced:
- Noisy operation;
- Leaking oil or hydraulic fluid;
- Reduced or loss of swing power;
- Difficulty in changing swing direction;
- Complete failure of the gearbox.
Maintenance Tips for Swing Gearbox
The following everyday maintenance practices can help extend the lifespan of your swing gearbox:
- Regularly check for oil leaks;
- Keep the gearbox clean and free of debris;
- Ensure the gear oil is regularly changed and topped up;
- Replace damaged seals or bearings immediately;
- Avoid overloading the excavator's upper structure beyond its capacity.
Compatible Excavator Brands and Models
Our Swing Gearbox can fit various excavator brands and models. Some common brands and models include:
- Caterpillar: 336D, 345D, 349D
- Komatsu: PC200-6, PC300-7, PC400-5
- Volvo: EC210B, EC240B, EC360B
About Us
We are a leading manufacturer of high-quality engineering machinery spare parts, including walking reducer assemblies, rotary reducer assemblies, gears, drive shafts, planetary gears, wheel hubs, pump casings, rotary shaft seats, end covers, gaskets, bearings, oil seals, and many other supporting products. Our products cover more than 12,000 types of transmission components for over 567 models of excavators and bulldozers. Our company is equipped with various production equipment, advanced processing technology, and a high-quality production design and marketing team.
Product Quick Detail:
- Standard and non-standard available
- With high quality and competitive price
- Prompt delivery
- Packing as per customer’s demand.
We promise will offer the best price by the high quality in china! We also accept special order about the products. If you are interested in our products. Please do not hesitate to let us know.We are pleased to give you the detailed information.We promise that our products would be safety and were in high quality and reasonable price. If you are interested in our products, please contact us asap.We are sincerely looking for your cooperation.
Most of our products are exported to Europe or Americas, both standard and nonstandard products available. We can produce as per your drawing or sample. Material can be standard or as per your special request. If you choose us, you choose reliable.

Materials Available
1. Stainless Steel: SS201, SS303, SS304, SS316, SS416, SS420
2. Steel:C45(K1045), C46(K1046),C20
3. Brass:C36000 ( C26800), C37700 ( HPb59), C38500( HPb58), C27200(CuZn37), C28000(CuZn40)
4. Bronze: C51000, C52100, C54400, etc
5. Iron: 1213, 12L14,1215
6. Aluminum: Al6061, Al6063
7.OEM according to your request
Surface Treatment
Annealing, natural canonization, heat treatment, polishing, nickel plating, chrome plating, zinc plating,yellow passivization, gold passivization, satin, Black surface painted etc.
Processing Method
CNC machining, punch,turning, milling, drilling, grinding, broaching, welding and assembly
QC & Certificate
Technicians self-check in production,final-check before package by professional Quality inspector
ISO9001:2008 , ISO14001:2001,ISO/TS 16949:2009
Package & Lead Time
Size: Drawings
Wooden Case/Container and pallet, or as per customized specifications.
15-25days samples. 30-45days offcial order
Port: Shanghai/Ningbo port


