CAT 117-7278 39mm Straight Bushing

CAT 117-7278 is a Caterpillar genuine straight-tube steel bushing, suitable for the boom, stick, or connecting rod hinges of loaders, excavators, and other equipment. It reduces friction, absorbs shock, and extends the life of the pins and mounting holes. The following is pure original data and does not include replacement parts information.

Core Technical Parameters (Raw Data)

Item Details
Basic Attributes Model 117-7278, Type: Straight-tube flangeless steel bushing, Fitting pin diameter: 50 mm, Single weight: 1.2 kg, Material: SAE 1050 alloy steel (surface hardened, hardness HRC 50-55), Suitable for grease lubrication, Operating temperature: -30℃ to +120℃, Load capacity: ≥90 kN

Key Dimensions (Metric/Imperial): Inner diameter: 50.0 mm (1.969 in, tolerance +0.02/-0 mm), Outer diameter: 60.0 mm (2.362 in, tolerance +0.03/-0 mm), Total length: 80.0 mm (3.150 in, tolerance ±0.1 mm), Wall thickness: 5.0 mm, Chamfered ends: 1×45°, Inner bore with lubrication groove and oil reservoir, Fitting mounting hole diameter: 60.0 mm mm (Tolerance + 0.01/-0 mm)

Performance Parameters: Coefficient of friction ≤0.1 (grease lubrication), fatigue resistance ≥10⁶ cycles, corrosion resistance rating IP65, radial runout of compatible pin ≤0.05 mm, clearance with pin 0.04-0.06 mm

Structure and Compatibility Characteristics:

High wear-resistant structure: Integral forging followed by precision grinding, surface hardening treatment, uniform hardness, suitable for high-frequency oscillation and heavy-load conditions, reducing wear on pins and bushings, extending component replacement cycles.

Optimized lubrication design: Internal spiral lubrication grooves and axial oil reservoir holes ensure uniform grease distribution, forming a stable oil film, reducing the risk of dry friction, suitable for intermittent lubrication or long-term operation.

Machine Compatibility: Compatible with the boom cylinder lugs, stick connecting rods, bucket pins, and other hinged parts of loaders such as 950K, 966K, and 980K, and excavators such as 320E, 323E, and 329E. Compatible pin models include 190-3524 and 190-3525.

Installation and Maintenance Points (Original Data)

Installation: Clean the bushings, pins, and mounting holes to remove oil, rust, and burrs. Check the dimensions with an inside and outside gauge; the clearance must meet the requirement of 0.04-0.06 mm.

Use cold-press installation with a special tool (such as 9D-9470). Control the installation pressure at 50-70 kN to ensure that the bushing end face is flush with the mounting hole end face, and the coaxiality tolerance is ≤0.05 mm.

After installation, apply lithium-based grease (NLGI 2). The grease should overflow from both ends of the bushing to ensure adequate lubrication.

Maintenance: Inspect the bushing for wear every 800 hours. Replace immediately if the inner diameter wear exceeds 0.2 mm or if scratches or peeling appear on the surface.

Regularly check lubrication points and replenish grease every 200 hours to prevent the bushing and pin from sintering due to insufficient lubrication.