CAT 422-6917 BEARING-GD

CAT 422-6917 is a Caterpillar original hydraulic cylinder trunnion spherical plain bearing (YM is the application code, referring to the trunnion part of the hydraulic cylinder). It is suitable for connecting the boom/stick cylinder trunnion and pin of excavators, loaders and other equipment. It can withstand radial loads and bidirectional oscillation, compensate for installation errors, and is a core wear part connecting the hydraulic cylinder and the working device. It can reduce the wear of the trunnion and pin and ensure smooth cylinder operation. Here are the core information and key points:

Core Technical Parameters

Item Details
Part Model: CAT 422-6917 (4226917) Hydraulic Cylinder Lug Joint Bearing, Original Equipment Manufacturer (OEM), no universal replacement model

Material: Outer ring chromium-molybdenum alloy steel (42CrMo), inner ring bronze alloy (CuSn12), surface hardened + cadmium plated passivation, inner ring with oil reservoir + PTFE self-lubricating liner, corrosion resistance ≥96 hours neutral salt spray test

Key Dimensions: Inner diameter 70mm, outer diameter 95mm, width 38mm, spherical radius R45mm, swing angle ±12°, compatible shaft diameter tolerance js6, lug seat hole tolerance H7, interference fit 0.03-0.05mm

Compatible Models: CAT 320D2/323D2 excavator, 966M/972M Used in loaders and other applications, specifically for the lower lugs of the boom cylinder and the lugs at both ends of the stick cylinder.

Performance Parameters: Rated radial load 180kN, rated static load 450kN, coefficient of friction ≤0.12 (grease lubrication), operating temperature -40℃ to 120℃, suitable for high-frequency oscillation and heavy-load conditions.

Core Functions and Structure:

Composite load-bearing and oscillation compensation: The spherical sliding structure can withstand radial loads and allows ±12° bidirectional oscillation, compensating for cylinder installation errors and angular deviations during operation, preventing the lugs and pins from jamming.

Self-lubricating and wear-resistant: The inner ring is made of bronze alloy + PTFE lining with an oil reservoir, eliminating the need for frequent grease injection, reducing friction and wear, suitable for harsh working conditions in construction machinery, and extending component life.

Anti-loosening positioning: The outer ring and lug seat hole have an interference fit, ensuring no loosening after installation, guaranteeing precise cylinder operation, and preventing cylinder rod bending or lug cracking caused by uneven load.

Corrosion Resistance: The cadmium-plated passivated outer ring resists corrosive environments such as damp and dusty construction sites, improving bearing durability.

Installation and Maintenance Points
Installation Specifications: Clean the clevis seat hole and pin to remove oil and rust. The seat hole roughness Ra≤1.6μm and roundness≤0.015mm. Use a special press-fit tool; do not directly strike the outer ring end face to prevent inner ring deformation.

After installation, check for smooth swing. Ensure there is no jamming and axial movement ≤0.2mm, ensuring a tight fit between the clevis and bearing.

Maintenance Recommendations: Check every 800 working hours: swing resistance and grease condition. Replenish with CAT DEO-ULS special grease. Replace every 2500-3000 working hours (adjust according to operating conditions).

Only genuine 422-6917 bearings must be used. Ordinary spherical plain bearings cannot be substituted to avoid premature failure due to incompatible materials, sizes, or lubrication structures, which could damage the hydraulic cylinder.