CAT 138-1843 149.3mm Inner Diameter Differential Seal Retainer

CAT 138-1843 is a Caterpillar original axle retaining ring (also commonly known as a snap ring/hole retainer). It is primarily used for axial positioning and anti-migration of components such as bearings, gears, pistons, or connecting rods in loaders, excavators, and other equipment. It is compatible with CAT 950G/962G loaders and some excavator models, and can stably lock components under vibration conditions, preventing component wear or failure caused by axial displacement.

Core Technical Parameters

Item Details
Part Model: CAT 138-1843 Shaft Elastic Retaining Ring (Fixer), corresponding to national standard GB/T 894.1 – 2017, alternative model can be referenced 620 – 080
Material: 65Mn spring steel, quenched and tempered, hardness HRC 42-52, surface galvanized passivation for corrosion protection, working temperature -40℃ to 120℃, elastic limit ≥1100MPa, fracture strength ≥1300MPa
Key Dimensions: Inner diameter 80mm, outer diameter 92mm, thickness 1.5mm, opening width 6mm, opening gap 0.8-1.2mm, suitable shaft groove diameter 80mm, groove width 1.6mm (tolerance +0.10/-0.05mm), groove depth 0.8mm
Compatible Models: CAT 950G/962G/966G Loader, 320C/325C excavator, used for axial fixing of drive axle wheel-side bearings, gearbox gear shafts, engine connecting rod bushings, hydraulic cylinder pistons, etc.

Performance Features: Flexible opening design facilitates installation and disassembly; hardened material provides good elasticity and fatigue resistance; galvanized passivation prevents rust; suitable for vibration conditions; quickly locks components to prevent axial movement, ensuring transmission accuracy and component stability.

Core Functions and Structure:
Axial Positioning and Anti-Movement: Installed in the annular groove of the shaft, it relies on its own elasticity to generate radial tension to hold the components in the groove, limiting axial displacement of bearings, gears, bushings, etc., preventing positional shifts caused by vibration and impact, and ensuring normal meshing and operational accuracy of the transmission system.

Simplified Installation and Maintenance: The flexible opening can be opened with snap ring pliers and then inserted into the shaft groove, requiring no complex tools and increasing installation efficiency; disassembly is also done with snap ring pliers, facilitating component inspection and replacement, reducing maintenance time and costs.

Lightweight and Low-Cost: Made of thin spring steel, it is lightweight, does not add extra load to the equipment, and has low manufacturing costs. It is an economical and efficient solution for axial fixing and is widely used in various mechanical transmission components.

Installation and Maintenance Points
Installation Specifications
Clean the shaft groove and retaining ring to remove oil, iron filings, and other impurities. Check that the shaft groove dimensions (diameter 80mm, groove width 1.6mm, groove depth 0.8mm) match the retaining ring, and that the groove walls are free of burrs and damage.

Use special external retaining ring pliers to open the retaining ring opening and smoothly place it into the shaft groove, ensuring that the retaining ring is fully embedded in the groove without any misalignment or jamming. After installation, manually rotate the retaining ring to confirm that it rotates freely without looseness.

After installation, check the axial clearance of adjacent components to ensure that the clearance meets the equipment’s technical requirements. Excessive clearance may cause component wobbling, while insufficient clearance may cause friction and jamming.

Maintenance Recommendations

Inspect every 1000 working hours: Check for deformation, breakage, and corrosion of the retaining ring; check for wear and enlargement of the shaft groove. If the retaining ring’s elasticity decreases, cracks appear, or it is severely corroded, it must be replaced immediately.

When replacing, only use original retaining rings of the same model to avoid mismatched sizes or material differences that could lead to fixing failure. Before installing a new retaining ring, clean the shaft groove and apply a small amount of grease to reduce friction damage during installation.