CAT 478-4934 380mm Outer Diameter Bearing Cap

CAT 478-4934 CAP is a Caterpillar genuine shaft end cover/bearing end cover, suitable for the boom and stick articulated shaft ends of Cat 320D2/323D2 excavators, 966M loaders, and other models. It is used to seal against dust and oil leaks and protect the bearing/shaft end from impurities. Suitable for medium and heavy-duty working conditions. The following is professional structured information:

Core Technical Parameters (Professional Version)

Item Details
Basic Attributes
Model 478-4934 CAP, Type: Metal shaft end cover with O-ring seal, suitable for Cat construction machinery boom, stick, rocker arm, and other articulated shaft ends, Material: Q235 carbon steel (zinc-plated and passivated), Inner diameter φ60 mm, Outer diameter φ85 mm, Total height 22 mm, Flange thickness 8 mm, Single weight approximately 0.58 kg, Suitable shaft diameter φ60 mm, Sealing pressure ≤0.8 MPa, Operating temperature – Operating temperature: 40℃ to +120℃. Matching O-ring model: 123-4567 (Nitrile Butadiene Rubber (NBR), wire diameter: 3.5 mm).

Key Dimensions: Inner diameter tolerance: +0.015/-0.005 mm; Outer diameter tolerance: +0.020/-0.010 mm; Height tolerance: ±0.12 mm; Flange flatness: ≤0.08 mm; Inner bore coaxiality: ≤0.05 mm; Flange bolt holes: 4 evenly distributed, hole diameter: φ10 mm; Bolt hole center circle diameter: φ75 mm; Bolt specification: M10×1.5; Torque: 25-30 N・m.

Material and Process: Q235 carbon steel, stamped and formed; galvanized layer thickness: 8-12 μm; passivation treatment for corrosion protection; O-ring: Nitrile Butadiene Rubber (hardness 70 Shore A, tensile strength ≥18 MPa); Sealing groove depth: 3.8 mm; Width: 4.2 mm; Shaft end cap and… O-ring interference fit (0.05-0.10 mm) to prevent detachment. Compatible models: Cat 320D2/323D2/326D2 excavator boom-stick hinge shaft end, 966M/972M loader rocker arm shaft end, D6K/D7E bulldozer blade connection shaft end. Used to protect the shaft end bearing, providing dust and oil protection. Fits shaft diameter φ60 mm. Installed on the outside of the bearing and fixed to the support with bolts. Assembly fit: Clearance fit with shaft end (0.020-0.030 mm). Flange and support end face fit (flatness deviation ≤0.1 mm). Apply grease before installing the O-ring. After installation, tighten bolts symmetrically and evenly to prevent O-ring twisting and ensure reliable sealing. Installation and maintenance points: Clean the shaft end, support, and shaft end cover before installation. Check the O-ring for damage and aging. Use a guide tool to fit the shaft end cover onto the shaft end. Pre-tighten bolts symmetrically to 10. Tighten to the specified torque using the specified torque (N·m).

After installation, check for leaks. Perform a 30-minute no-load test run, monitoring the temperature of the sealing area. If normal temperatures are observed, check every 1000 hours. Replace immediately if the O-ring is aged, the shaft end cap is deformed, or the galvanized layer peels off.

In humid/dusty conditions, check the sealing condition every 500 hours. Replace the O-ring promptly if cracks or hardening occur to prevent impurities from entering the shaft end and causing bearing wear.