CAT 625-7419 38.2mm Inner Diameter Lift Cylinder Bearing

CAT 625-7419 is a Caterpillar lift cylinder bearing with an inner diameter of 38.2mm. It is used for guiding, supporting, and protecting the piston and cylinder of hydraulic lift cylinders in loaders/excavators and other equipment. It is compatible with models such as 966M/972M/980M, ensuring smooth lifting, preventing uneven wear, and ensuring reliable sealing. The following is the core information:

Core Technical Parameters

Item Details
Part Model CAT 625-7419 (6257419) Lifting Cylinder Bushing Bearing, Inner Diameter 38.2mm, Fits Piston Rod Diameter 38mm, Used for piston guidance and wear protection in lifting cylinders (Cat®…)

Material Low carbon alloy steel + tin-plated/cadmium-plated surface for corrosion resistance, precision honing of inner bore Ra≤0.6μm, hardness HRC 58-62, suitable for hydraulic conditions from -40℃ to 120℃, resistant to hydraulic oil corrosion

Key Dimensions Inner Diameter 38.2mm, Outer Diameter 48mm, Length 60mm, Wall Thickness 4.9mm, Chamfered Ends 1×45°, Fits Piston Rod Diameter 38mm, Cylinder Inner Diameter 120mm, Single Weight Approx. 0.21kg

Compatible Models CAT 966M/972M/980M This product is suitable for loaders, 320GC/336GC excavators, 988K mining loaders, etc., and is designed for lifting cylinder working pressure ≤35MPa and piston speed ≤0.5m/s.

Performance Parameters: Radial runout ≤0.04mm, clearance 0.05-0.10mm, fatigue strength ≥850MPa, impact and extrusion resistant, no deformation or jamming after long-term use, and compatible with high-pressure hydraulic systems.

Core Functions and Structural Features:

Guidance and Support: Provides radial positioning for the lifting cylinder piston, limiting piston offset to ≤0.1mm, ensuring piston and cylinder coaxiality, reducing uneven wear, and extending seal life.

Wear-Resistant Protection: The inner wear-resistant layer reduces the piston rod and cylinder friction coefficient to below 0.08, suitable for high-load, high-frequency reciprocating conditions, and reducing direct metal-to-metal contact wear.

Sealing Assistance: Fills the microscopic gap between the piston and cylinder, suppresses hydraulic oil leakage, and, in conjunction with the seals, improves cylinder volumetric efficiency, ensuring stable lifting power.

Installation and Fit: Standard size fits the piston mounting slot of the lifting cylinder, with an interference fit of 0.03-0.05mm. No additional machining is required after installation. Compatible with Cat® quick-repair system…

Installation and Maintenance Points

Installation Specifications: Clean the inner wall of the cylinder, piston groove, and bearing outer surface to remove oil, metal filings, and burrs. Ensure there are no scratches or rust. Check the piston groove roundness to ≤0.02mm.

Use a special press to press the bearing into the piston groove with a pressure of 5-8kN, or cool the bearing with liquid nitrogen (-196℃) before quick assembly. Ensure an interference fit of 0.03-0.05mm to avoid damaging the piston and bearing.

After installation, check the smooth sliding of the piston rod and bearing to ensure there is no jamming, smooth piston reciprocating motion, and a coaxiality error ≤0.05mm.

Maintenance Recommendations:
Inspect bearing wear every 5000 working hours or during a major overhaul. Replace the bearing if the inner bore wear is ≥0.15mm or if surface scratches/peeling are observed to prevent seal failure and weak lifting.

Simultaneously check the hydraulic oil cleanliness (NAS 1638 grade ≤8). Oil contamination accelerates bearing wear; regular filter and hydraulic oil replacement is recommended.