CAT 343-5371 100.25mm Outer Diameter Planetary Carrier Retainer

The CAT 343-5371 is a Caterpillar original heavy-duty spring retainer, primarily used for positioning bucket teeth (GET), connecting rod pins, or bearing end caps on excavators, loaders, and other equipment. It uses elastic preload to lock the pin/component, preventing axial movement. It is suitable for high-frequency impact conditions in Cat® models such as the 320D2/336D2 and 950L/962L…

Core Technical Parameters

Item Details
Part Model CAT 343-5371 Spring Retainer

Material 65Mn spring steel, galvanized and passivated surface, elastic limit σe≥800MPa, hardness HRC 42-48, impact fatigue resistant, rust prevention level reaches 48h salt spray test with no red rust

Key Dimensions Inner diameter approx. 32mm, outer diameter approx. 45mm, thickness approx. 8mm, elastic opening width 5mm, preload approx. 12-15kN, compatible with 32mm diameter pins/shaft ends, positioning groove depth ≥3mm

Compatible Models Compatible with 320D2/323D2/336D2 excavators, 950L/962L loaders, 430F2 loaders, etc., used for bucket tooth pin locking, boom connecting rod pin positioning, bearing end cap anti-loosening, cylinder lug fixing, etc.

Performance Characteristics Open-type elastic structure, automatically springs back and tightens after installation, impact-resistant and anti-loosening, stable operation from -40℃ to 120℃, suitable for high-frequency vibration and heavy-load impact conditions in engineering machinery, with a repetitive disassembly life of ≥50 times.

Core Functions and Structure

Elastic Locking: The open-type spring steel body, during installation, elastically deforms and engages with the pin positioning groove, relying on the rebound preload to tighten the pin, preventing axial movement of the component and preventing pin detachment and abnormal noise.

Anti-Loosening and Vibration Prevention: Suitable for high-frequency vibration conditions, the elastic structure absorbs impact loads, preventing the retainer from loosening. Compared to cotter pins/circlips, it has higher anti-loosening reliability and is suitable for heavy-load and continuous operation scenarios.

Quick Installation and Removal: No special tools required, can be installed and removed by hand/circlip pliers, suitable for quick on-site equipment maintenance, reducing downtime and improving work efficiency.

Positioning and Guiding: Precise inner diameter dimensions ensure coaxiality between the pin and the mounting base, avoiding uneven wear. When used with bushings/bearings, it extends the overall life of the component.

Installation and Maintenance Points

Installation Specifications
Clean the pin positioning groove and the surface of the retainer to remove oil, rust, and impurities; check that the retainer is free from deformation and cracks, the elastic opening is undamaged, and its dimensions meet assembly requirements.

Use snap ring pliers to open the elastic opening and insert the retainer into the pin positioning groove, ensuring the retainer is fully embedded in the groove, with the end face fitting snugly against the pin/component without gaps. After installation, gently pull the retainer; it should not be loose.

Before installation, apply a small amount of lithium-based grease to the pin positioning groove to reduce friction between the retainer and the pin, prevent rust and jamming, and facilitate subsequent disassembly.

Maintenance Recommendations
Inspect every 500-800 working hours: Check the retainer for deformation, elasticity loss, and surface rust. Replace it immediately if elasticity failure or cracks are found to prevent pin detachment and subsequent malfunctions.

Under heavy load/dusty conditions, simultaneously check the wear of the pin positioning groove. Repair or replace the pin if the groove depth wear exceeds 0.5mm to ensure the retainer preload meets specifications.