CAT 392-5537 Articulating Hitch Lower Cap

CAT 392-5537 is a Caterpillar original bearing end cap (CAP, shaft end seal cover), compatible with the steering drive axle of Cat 140M/160M graders and the output shaft end of the gearbox of 938G loaders. Its core function is to seal the bearing cavity, prevent dust and leakage, and position the outer ring of the bearing. It is suitable for shaft end protection under medium- and low-speed heavy-load conditions. The following are the professional parameters and application guidelines:

Core Technical Parameters (Professional Version)

Item Details Basic Attributes Model 392-5537, Type Bearing End Cap (CAP, with O-ring seal groove, cast iron material), Compatible with Cat 140M/160M grader steering drive axle differential end cap, 938G loader gearbox output shaft bearing end cap, Material QT500-7 ductile iron (HB 170-230, tensile strength ≥500 MPa), Outer diameter φ140 mm, Inner diameter φ80 mm, Total thickness 25 mm mm, single weight approximately 1.2 kg, O-ring groove compatible with 3K-0360 (nitrile rubber NBR, wire diameter φ5 mm), operating temperature -40℃ to +120℃, rated sealing pressure ≤0.3 MPa Cat® Parts
Key Dimensions: Outer diameter tolerance 0/-0.020 mm, inner diameter tolerance +0.015/-0.010 mm, thickness tolerance ±0.12 mm, number of bolt holes 4 (evenly distributed, diameter φ12 mm, center circle diameter φ120 mm), O-ring groove diameter φ100 mm, width 5.5 mm, edge chamfer 1×45°, compatible bearing 2J-2161 (single row tapered roller bearing), mounting surface flatness ≤0.05 mm, end face runout ≤0.03 mm Cat® Parts
Material and Process: Material QT500-7 ductile iron, resin sand casting + Aging treatment (to relieve internal stress), surface phosphating treatment (salt spray resistance ≥96 hours), CNC precision milling of sealing grooves (roughness Ra≤1.6 μm), bolt hole tapping M12×1.75 (depth 15 mm), O-ring groove surface free of porosity/shrinkage, compatible with NBR nitrile rubber O-rings (oil-resistant/wear-resistant, compatible with mineral oil-based lubricants)

Compatible models: Cat 140M/160M grader (serial number JDH1200-UP) steering drive axle differential end cover, 938G loader (serial number KAT800-UP) gearbox output shaft bearing end cover. Its core function is to seal the bearing cavity, preventing lubricant leakage and dust/moisture intrusion, while also positioning the bearing outer ring to ensure stable bearing clearance. Suitable for low-to-medium speed, heavy-load impact conditions.

Assembly and mating: End cover bolted to housing (torque 80-100 N・m), O-ring pre-compression. Apply 15%-20% (Cat 2V lithium-based grease before installation). After installation, check the end cap face runout to be ≤0.03 mm, radial runout to be ≤0.02 mm, and the gap between the end cap and bearing outer ring face to be ≤0.05 mm. Installation and Maintenance Points: Before installation, clean the end cap, housing mounting surfaces, and O-ring grooves. Check for cracks, porosity, and rust. Ensure the O-rings are undamaged. Apply Cat 2V lithium-based grease to the O-ring surface to enhance sealing performance.

During assembly, first place the O-ring into the groove, then align the bolt holes. Tighten the bolts evenly in 2-3 stages (torque 80-100 N·m) to avoid localized stress that could deform the end cap or damage the O-ring.

Maintenance Recommendations: Check the end cap seal every 1500 hours. Replace immediately if oil leakage or O-ring aging (hardness change > ±5 Shore A) occurs to prevent bearing cavity lubrication failure.