CAT 425-6439 BEARING-GD

CAT 425-6439 is a Caterpillar genuine YM straight sleeve bearing (shoulder sleeve), suitable for the pivot parts of tracked machinery’s walking and working devices. The following is purely precise information (no additional description):

Core Parameters and Information

Item Details
Part Model: CAT 425-6439 (4256439) YM Straight Sleeve Bearing

Part Type: YM series straight sleeve bearing, used in the mating parts of track frames, connecting rods, and pivots, bearing radial loads, suitable for medium-low speed heavy-duty conditions, used in conjunction with the CAT 425-6440 pin

Material: SAE 8620 low-carbon alloy steel, surface carburized and quenched + tempered, hardness HRC58-62, precision ground inner bore, roughness Ra≤0.4μm, suitable for lithium-based grease and mineral oil lubrication

Key Dimensions: Inner diameter 50.80mm (2.0000in), outer diameter… 62.00mm (2.4409in), total length 63.50mm (2.5000in), wall thickness 5.60mm, chamfered ends 1×45°, fit tolerance H7/s6
Structural features: No oil groove or oil hole (suitable for centralized lubrication systems), flangeless straight cylinder structure, rated radial load 180kN, operating temperature -25℃ to 120℃, static radial clearance 0.012-0.022mm
Compatible structures: Tracked bulldozer track frame pivot, loader rocker arm connecting rod sleeve bearing, suitable pin outer diameter 50.80mm, mounting hole inner diameter 62.00mm, installation interference 0.018-0.028mm
Applicable working conditions: Tracked machinery walking mechanism, working device connecting rod rotating parts, speed ≤800rpm, radial load ≤150kN, suitable for lithium-based grease (NLGI) 2) Compatible Models and Assemblies

Bulldozers: CAT D5K2, D6K2, D6N (track frame pivot sleeve bearing assembly)

Loaders: CAT 938K, 950L (rocker arm connecting rod sleeve bearing assembly)

Graders: CAT 120M, 140M (working device connecting rod sleeve bearing assembly)

Compatible Assemblies: D6K2 track frame pivot sleeve bearing assembly, 938K rocker arm connecting rod sleeve bearing assembly

Installation and Fitting Points

Before installation, clean the mounting holes and the outer diameter of the sleeve, ensuring no burrs or rust. Use cold pressing installation, pressing in with a special press tool. Do not directly strike the bearing end face to prevent deformation.

After installation, the bearing should have an interference fit with the mounting hole (0.018-0.028mm) and a clearance fit with the pin (0.012-0.022mm) to ensure smooth and unobstructed rotation.

After assembly, check that the coaxiality is ≤0.02mm. Apply grease promptly after installation to ensure adequate lubrication.

For disassembly, use a dedicated puller to remove the bearing. Do not pry the bearing edges. When replacing, check the wear on the pin and mounting hole. If the wear is >0.05mm, repair or replacement is required.