CAT 456-5279 COVER

CAT 456-5279 is a Caterpillar steel shaft end cover, adapted for the output shaft end of the swing gearbox and the flange end of the travel motor of Cat 320/323/326 series excavators. It is used to seal against dust and oil leakage and protect the shaft end bearings/seals, preventing the intrusion of foreign matter that could cause component wear and failure. It is a key protective component for the transmission system. The following is structured technical and application information:

Core Technical Parameters

Item Details
Basic Attributes
Model 456-5279, Type: Shaft End Protective Cover, Material: Q345B Alloy Steel (Powder Coated), Weight: Approx. 2.8 kg, Applicable Temperature: -40℃ to +120℃, Sealing Method: O-ring Seal, Installation Method: Bolt Fastening (8 M10×1.5 Bolts, Torque 45-50 N・m), Protection Rating: IP65, Suitable Shaft Diameter: 80 mm, Surface Coating Thickness: 60-80 μm

Key Dimensions
Outer Diameter: 120 mm (Tolerance ±0.15 mm), Inner Diameter: 80 mm (Tolerance H8, +0.054/+0.000 mm), Total Thickness: 25 mm (Tolerance ±0.10 mm), Flange Width: 15 mm, Bolt Hole Distribution Circle Diameter: 100 mm, Bolt Hole Diameter: 10.5 mm (8 evenly distributed), O-ring Groove Diameter 90 mm groove width, 3 mm groove depth, 2.5 mm surface roughness Ra≤1.6 μm
Compatible Models and Applications: Compatible with the output shaft end of the boom slewing gearbox of Cat 320GC, 323GC, and 326GC excavators, and the flange end connecting the travel motor and drive axle. Matching parts include 4V-9521 O-rings and 12-P-1234 bolts for dust and oil protection at the shaft end, protecting bearings and seals, and extending the life of transmission components.

Performance Parameters: Tensile strength ≥510 MPa, yield strength ≥345 MPa, impact toughness ≥50 J/cm², coating adhesion grade 1 (cross-cut test), corrosion resistance meets ISO 9227 neutral salt spray test (96 hours rust-free), can withstand axial static load ≤80 kN, operating speed ≤300 rpm

Structural and Performance Advantages: High-protection seal: Alloy steel material + powder coating, balancing strength and corrosion resistance, IP65 The high protection rating effectively prevents dust and mud from entering the shaft end. The O-ring seal design prevents lubricant leakage, ensuring the cleanliness and lubrication of the transmission system.

Precise positioning and fastening: Strict dimensional tolerances and precise bolt hole distribution ensure a tight fit with the shaft end after installation, with no radial movement. Standard bolt tightening torque ensures long-term stability and prevents seal failure and component damage due to vibration.

Wear-resistant and impact-resistant: The Q345B material possesses excellent toughness and tensile strength, capable of withstanding impact loads during operation. The powder-coated surface reduces friction and wear, extending the service life by approximately two times compared to ordinary carbon steel covers, reducing replacement frequency.

High versatility: Compatible with key shaft end areas of various 320/323/326 series excavators, requiring no custom installation tools, facilitating maintenance and replacement, and reducing inventory and maintenance costs.

Installation and Maintenance Points:
**Before installation, clean the shaft end, flange face, and sealing groove of the cover to remove burrs, rust, and oil.** Install the 4V-9521 O-ring (apply a small amount of grease), align the cover with the bolt holes, and tighten evenly with 12-P-1234 bolts, controlling the torque to 45-50 N·m to avoid localized stress that could lead to deformation or seal failure.

Every 1000 hours of maintenance, check the cover’s tightness, coating integrity, and O-ring aging. If loosening, coating peeling, or O-ring cracking is found, tighten or replace it immediately. Check the shaft end for oil leaks and dust accumulation; clean and reseal to prevent accelerated component wear.

Prioritize original parts. Aftermarket parts must guarantee material strength, dimensional accuracy, and coating quality. Inferior shaft end covers can easily lead to seal failure and shaft end bearing wear, increasing maintenance costs and downtime.