CAT 173-7761 164mm Outer Diameter Bearing Cap

CAT 173-7761 is a Caterpillar genuine bearing end cap/seal cap (suitable for Cat 320D/323D2 excavator slewing bearings, 336D engine accessory drive shafts, etc., used for sealing against dust, fixing the bearing, and protecting the internal grease; the following is pure original data and does not include replacement parts information).

Core Technical Parameters (Raw Data)

Item Details
Basic Attributes
Model: 173-7761; Type: Bearing end cap (with O-ring seal); Material: Low carbon steel (Q235) + Nitrile rubber (NBR); Weight: 0.32 kg; Operating temperature: -30℃ to +100℃; Compatible with: Lithium-based grease (NLGI 2); Sealing pressure: ≤0.3 MPa; Oil resistance: Compatible with mineral oil/synthetic gear oil; Impact strength: ≥20 J/cm²

Key Dimensions
Outer diameter: 95 mm (3.740 in); Inner diameter: 62 mm (2.441 in); Thickness: 12 mm (0.472 in); Bolt hole diameter: 10 mm (3 locations, evenly distributed); Bolt hole center circle diameter: 80 mm; O-ring groove diameter: 75 mm; Groove width: 2.5 mm; Chamfer: r1.0 mm; Flatness: ≤0.05 mm; Surface roughness: Ra 1.6 μm; Hardness: HB 120-150, O-ring diameter 2.4 mm (NBR, hardness 70 Shore A)

Compatible Models and Parts: Compatible with Cat 320D/323D2 excavator slewing bearing end caps (position 12, 1 piece per part), 336D engine accessory drive shaft bearing end caps, and also compatible with end seals for drive bearings of some loaders and bulldozers. Used to fix the bearing outer ring, prevent dust/moisture intrusion, ensure grease sealing, and extend bearing life.

Performance Parameters: Sealing performance: Static leakage ≤0.01 cm³/h, dynamic leakage ≤0.05 cm³/h (speed ≤1500 rpm); Wear resistance ≥6000 hours (normal operating conditions); Bearing fit accuracy H8, Seat fit accuracy H7, Bolt preload torque 18-22 N・m

Structural and Performance Advantages: Steel + Rubber Composite Structure: Low-carbon steel base ensures structural strength and installation accuracy, NBR O… The O-ring provides a reliable seal, adaptable to the vibration and temperature variations of complex operating conditions in engineering machinery.

Evenly Distributed Bolt Hole Design: Three evenly distributed bolt holes ensure uniform force distribution during installation, preventing end cap deformation and guaranteeing sealing performance. Suitable for the fixing requirements of high-speed rotating components such as slewing bearings and drive shafts.

Precise O-Ring Groove Machining: Strictly controlled groove dimensional accuracy ensures compatibility with standard NBR O-rings. Stable sealing pressure effectively prevents grease leakage and external impurities from entering, reducing the risk of bearing wear.

Installation and Maintenance Points (Original Data)

Installation: Clean the end cap and bearing housing sealing surfaces. After inspecting for damage, insert the O-ring into the groove. Use a torque wrench to tighten the bolts diagonally (pre-tightening torque 18-22 N·m). The rear end face runout should be ≤0.08 mm to ensure a good seal without gaps.

Maintenance: Check bolt tightness every 1000 hours and tighten to the specified torque if necessary; check O-ring aging/wear every 2000 hours, and replace immediately if cracks or hardening are found; avoid using corrosive cleaning agents when cleaning the sealing surfaces to prevent damage to the O-ring and end cap surfaces.

Troubleshooting: If grease leakage occurs, check for damaged O-rings and loose bolts, and replace or retighten the O-rings promptly; if the end cap is deformed, replace the end cap to prevent premature bearing damage due to seal failure.