CAT 117-7280 32mm Outer Diameter Piston Pump Bushing

CAT 117-7280 is a Caterpillar original 4140 chromium molybdenum steel hardened bushing (sleeve bearing), suitable for the articulation parts of excavators, loaders and other equipment, used for radial support and low friction rotation under heavy load and impact conditions. The following is the core information:

Core Technical Parameters

Item Details
Part Model: CAT 117-7280 (Hardened Steel Bushing with Axial Lubrication Groove)

Material: Base material 4140 chromium-molybdenum steel, inner hole surface hardening hardness HRC 58-62, hardened layer thickness 0.8-1.2 mm; surface with axial lubrication groove, compatible with oil/grease lubrication

Key Dimensions: Inner diameter 50.8 mm (2,000 in), outer diameter 63.5 mm (2,500 in), length 50.8 mm (2,000 in), chamfer radius 0.8 mm, wall thickness 6.35 mm

Unit Weight: Approx. 0.15 kg (0.331 lbs)

Tolerances: Inner diameter tolerance H7 (+0.030/0 mm), outer diameter tolerance g6 (0/-0.019 mm), length tolerance ±0.10 mm, inner hole surface roughness Ra ≤ 0.4 μm
Core Characteristics: Radial load capacity 95 kN, static allowable load 130 kN, operating temperature -40℃ to +130℃, coefficient of friction 0.08-0.12 (grease lubrication)
Structure and Core Functions:
Heavy-duty and wear-resistant: 4140 chromium-molybdenum steel base + surface hardening, suitable for heavy-duty hinged parts such as boom cylinder lugs and stick pins, resistant to impact and abrasive wear.

Optimized lubrication: Inner bore axial lubrication groove + circumferential oil reservoir ensures uniform lubrication, reduces dry friction, suitable for intermittent operation and harsh working conditions of construction machinery.

Clearance compensation: Recommended clearance with pins 0.04-0.08 mm, compensates for manufacturing errors and wear, ensures flexible rotation, and reduces the risk of abnormal noise and jamming.

Easy installation: Thin-walled cylindrical structure, can be cold-pressed or liquid nitrogen-shrink-installed, suitable for compact spaces, no complex tooling required.

Compatible Models and Application Scenarios

Compatible Equipment: CAT 312, 313 excavators, 908, 910 loaders, 420F, 430F backhoe loaders, etc.

Core Applications: Installed on boom cylinder lugs, stick cylinder pins, steering linkage pins, bucket hinge points, etc., providing heavy-duty support and low-friction rotation, suitable for high-frequency oscillation and impact conditions.

Installation and Maintenance Points

Installation: Clean the mounting holes and bushing surfaces, ensuring no deformation, cracks, or burrs; apply a pressing force of 10-15 kN, using a dedicated press head to press evenly, avoiding striking the end face to prevent damage to the hardened layer.

After installation, coaxiality ≤ 0.05 mm, clearance 0.04-0.08 mm, and rotation without jamming.

Maintenance: Grease lubrication: Add NLGI Grade 2 lithium-based grease every 500 hours, until overflowing; oil lubrication uses CAT HYDO 10 hydraulic oil, with continuous oil supply. Regularly check for gaps and abnormal noises. Replace the pin promptly if the gap exceeds 0.20 mm or if there is abnormal wear, to avoid excessive wear on the pin and mounting hole.