CAT 151-7490 BUSHING

CAT 151-7490 is a steel-backed PTFE bronze straight-tube bushing (also known as a flangeless sleeve bushing) for Caterpillar engineering machinery. It is fitted to the boom, stick, cylinder pin holes, or connecting rod joints of excavators and loaders to support swing/rotational motion and bear radial loads. The following is precise technical and application information:

Core Technical Parameters
Item Details
Part Model: CAT 151-7490 (1517490) Straight-tube Bushing, weighing approximately 0.58 kg (1.28 lb), flangeless straight-tube structure with circumferential lubrication grooves and radial oil injection holes.

Core Materials: Steel backing (42CrMo alloy steel, tempered hardness HB 260-290, copper-plated surface); Anti-friction layer (bronze + PTFE composite material, containing 15% solid lubricant, coefficient of friction ≤0.08, suitable for dry/oil lubrication conditions); Wear-resistant layer thickness 0.8-1.0 mm, bonding strength ≥150 MPa

Key Dimensions: Inner diameter 50.8 mm (2.00 in), outer diameter 63.5 mm (2.50 in), total length 76.2 mm (3.00 in), wall thickness 6.35 mm, lubrication groove width 2 mm, depth 0.5 mm, oil injection hole diameter 4 mm, 4 holes evenly distributed circumferentially

Rated Parameters: Rated radial dynamic load 120 kN, rated radial static load 240 kN, suitable temperature -40℃ to +120℃, coefficient of friction (dry friction) ≤0.10, (oil lubrication) ≤0.05, suitable swing angle ±30°, suitable pin diameter 50.8 mm

Suitable Working Conditions: Medium to heavy-duty swing/rotating parts, suitable for dusty and vibrating engineering machinery conditions, used for boom and stick connection, cylinder lugs, connecting rod joints, bearing radial loads, not suitable for pure axial load conditions

Compatible Models: CAT 320D/323D Excavator (boom cylinder lugs), 950G/966H loader (stick pins), 307E2 excavator (stick and bucket connection), 420F loader (steering linkage)

Supporting Parts: Fitting pins 151-7491, grease nipples 1U-8878, retaining rings 5K-8591, installation tools 107-7775 (63.5 mm pressure head)

Core Functions and Structural Features:

Low Friction and Wear Resistance: Steel backing + bronze + PTFE composite structure, low coefficient of friction, suitable for oil-free/low-oil conditions, reducing wear on pins and bushings, extending component life.

Highly Efficient Lubrication: Circumferential lubrication grooves + radial oil injection holes design, uniform grease distribution, suitable for long-term oscillating/rotating conditions, reducing maintenance frequency.

High Load Capacity: Steel backing provides high rigidity, composite anti-friction layer suitable for medium and heavy loads, suitable for impact loads, reducing deformation and vibration.

Easy Installation: Flanged, straight-tube structure allows for quick installation using press-fit tools, facilitating on-site maintenance and reducing downtime.

Wide Compatibility: Compatible with various lubricating media such as mineral oil and synthetic oil, adaptable to common temperatures and operating conditions in construction machinery, offering high versatility.

Installation and Maintenance Points
Installation Specifications: Clean the pin hole and bushing surface, removing burrs, oil, and impurities. Check for bushing deformation and absence of friction-reducing layer peeling.

Cold installation (room temperature press-fit): Apply pressure evenly to the steel backing end face to avoid stress damage to the friction-reducing layer. After installation, the bushing end face should be flush with the pin hole.

After installation, inject grease and check for any jamming during oscillation/rotation, abnormal noise, and clearance meeting equipment requirements (typically 0.05-0.10 mm).

Maintenance Recommendations: Replenish grease every 250 working hours, injecting until new grease overflows each time to ensure adequate lubrication.

Check the bushing wear every 1000 working hours. Replace it promptly when the inner diameter wear exceeds 0.5 mm or the clearance is greater than 0.2 mm.