CAT 478-4932 CAP

CAT 478-4932 is a Caterpillar original metal shaft end cap (CAP) suitable for crankshaft/camshaft ends, hydraulic cylinder piston rod heads, or transmission system flanges in Cat C15/C18 engines, 777F mining trucks, D10T bulldozers, and other models. It provides dust, oil, and foreign object impact protection. It weighs approximately 0.18 kg. The following is professional structured information:

Core Technical Parameters (Professional Version)

Item Details
Basic Attributes
Model 478-4932, Material: Q235 carbon steel + galvanized passivation (corrosion resistance IP65), Outer diameter φ45 mm, Inner diameter φ30 mm, Total height 18 mm, Weight 0.18 kg, with O-ring seal (NBR material, wire diameter 2.65 mm), threadless, uses snap-fit ​​+ interference fit installation, Operating temperature -40℃ to + 120℃, impact strength ≥5 J/cm², suitable for mounting positions with shaft end diameter φ30 mm±0.02 mm

Key Dimensions: Inner diameter tolerance +0.01/-0.005 mm, outer diameter tolerance +0.02/-0.01 mm, end face flatness ≤0.03 mm, inner hole surface roughness Ra≤3.2 μm, outer diameter Ra≤1.6 μm, snap-fit ​​thickness 1.5 mm, O-ring groove diameter φ35 mm, groove width 3 mm

Material and Process: Q235 carbon steel, stamped and formed, surface galvanized and passivated (film thickness 8-12 μm), tensile strength ≥370 MPa, hardness HB 100-120, O-ring made of NBR material (Shore hardness 70±5), oil-resistant and aging-resistant, sealing pressure ≤0.8 MPa, uncoated, can withstand moderate impact and vibration

Compatible Models: Compatible with Cat C15/C18 engine crankshaft front end/camshaft rear end protection, 777F mining truck driveshaft flange end cover, D10T bulldozer hydraulic cylinder piston rod head dust cover, 988K loader steering knuckle shaft end protection, also used for bearing end cover protection in some Cat 3516B generator sets.

Assembly fit: Interference with shaft end 0.01-0.02 mm. During installation, gently tap with a rubber mallet to ensure the O-ring is fully embedded in the groove. The clearance between the rear end face and the shaft end plane should be ≤0.1 mm, with no looseness or eccentricity. Disassembly requires a special clip screwdriver; do not pry or pry to the shaft end.

Installation and maintenance points: Clean the shaft end and mounting position before installation. Check for damage or deformation of the O-ring, and ensure the shaft end is free of burrs and rust. During installation, align with the clip groove and tap the end face evenly with a rubber mallet until the clip is fully engaged in the mounting seat groove.

After installation, check that the coaxiality between the cover and the shaft end is ≤0.05 mm, with no wobble, and that there is no leakage at the O-ring. For applications exposed to dusty/humid conditions for extended periods, check every 1500 hours. Replace immediately if rust, deformation, or seal failure is found.

When disassembling, use a special clip screwdriver inserted into the gap between the cover and the mounting base, applying even force to pry it open. Avoid damaging the clips or the threads/surface of the shaft end. Replace the O-ring simultaneously to prevent poor sealing.