Axle Box Shimming Tool – Product Description

Product Overview

The Axle Box Shimming Tool is a specialized maintenance device designed for the adjustment of primary suspension spring height in railway vehicles, including high-speed EMUs, metro vehicles, and locomotives. Manufactured by Yunxin Intelligent Equipment (Chengdu) Co., Ltd.—a National High-tech Enterprise with ISO 9001 certification and AAA corporate credit rating—this tool enables precise shim insertion or replacement beneath the primary suspension spring without the need for vehicle lifting or bogie disassembly.

In railway vehicle assembly and maintenance, national standards require that the wheel load imbalance on the same wheelset must not exceed 4%, and axle load imbalance must not exceed 2%. When these parameters fall outside the acceptable range, the height of the primary suspension spring must be adjusted by adding or replacing shims beneath the spring. Traditionally, this adjustment required lifting the vehicle, disassembling the bogie, and removing the wheelset—a process that was time-consuming and labor-intensive. The Axle Box Shimming Tool eliminates these cumbersome steps, allowing maintenance crews to perform shim adjustments quickly and safely in confined spaces.

As part of Yunxin‘s comprehensive portfolio of urban rail transit special tooling, the Axle Box Shimming Tool joins a product line that includes transport trolleys, coupler disassembly trolleys, aluminum alloy combination ladder trucks, and metro door disassembly equipment. Built to the rigorous standards of the railway industry, it delivers reliable performance in demanding maintenance environments.

Key Features

No-Vehicle-Lifting Operation – The tool enables shim adjustment without lifting the vehicle body or disassembling the bogie. Maintenance crews can perform the adjustment directly in the workshop pit or on the trackside, eliminating the need for heavy lifting equipment and significantly reducing downtime.

Hydraulic Lifting Mechanism – Equipped with a hydraulic pump and cylinder system, the tool safely compresses the primary suspension spring to create sufficient clearance for shim insertion or removal. The hydraulic system is operated via a dual-circuit manual hydraulic pump, which is compact, lightweight, portable, and safe.

Precise Shim Adjustment – The tool allows for accurate shim thickness selection and placement, ensuring that wheel load balance and axle load distribution meet the required design specifications of ≤4% wheel load imbalance and ≤2% axle load imbalance.

Simple and Reliable Design – Featuring a robust support plate, threaded bolts, and a lower clamp plate that securely engages the spring, the tool provides stable and controlled spring compression. The bolt head is recessed into a cavity on the support plate to prevent slipping during the lifting process.

Space-Saving Operation – The compact design allows the tool to operate in the narrow clearance between the bogie frame and the wheelset, making it ideal for use in maintenance pits and confined workshop spaces.

Time and Labor Savings – Compared to traditional methods that require vehicle lifting, bogie disassembly, and wheelset removal—often taking several hours—the Axle Box Shimming Tool reduces adjustment time to minutes. A single technician can complete the operation without the need for overhead cranes or drop tables.

Technical Specifications (Typical)

Applications

• High-Speed EMU Maintenance Depots – Primary suspension shim adjustment during routine overhauls and wheel load balancing procedures.

• Metro & Urban Rail Vehicle Yards – Quick adjustment of primary spring height to maintain floor height and ensure passenger comfort.

• Locomotive Maintenance Facilities – Wheel load distribution adjustment for heavy-haul and passenger locomotives.

• Railcar Manufacturing & Final Assembly – Post-assembly wheel load balancing before vehicle delivery.

• Bogie Overhaul Workshops – Shim replacement during primary suspension refurbishment.

Why Choose Yunxin‘s Axle Box Shimming Tool?

• Proven Technology – The design is based on industry-proven principles and has been successfully deployed in railway maintenance depots nationwide.

• Industry Expertise – Backed by a technical team of 2 senior engineers, 5 engineers, and 10 specialized technicians with deep knowledge of railway bogie systems and maintenance tooling.

• Customer Trust – A qualified supplier to China Railway Chengdu Bureau, Xi‘an Bureau, Guangzhou Bureau, and other railway bureaus, as well as CRRC Qingdao Sifang and CRRC Digital Technology.

• Quality Assured – Manufactured under ISO 9001 quality management system, ensuring consistent product reliability and safety.

• Full-Service Support – From design and customization to production, delivery, and after-sales maintenance, Yunxin provides end-to-end service.

Custom Orders Welcome

Yunxin Intelligent Equipment offers tailored Axle Box Shimming Tool solutions to meet specific operational requirements. Whether you need modified lifting capacity, customized spring engagement components, or adaptations for different vehicle models, our engineering team can design and build a tool that fits your exact needs.