CAT 7U-7345 Flanged Sleeve Bearing

CAT 7U-7345 is a Caterpillar Straight Steel Bushing, primarily designed for use in the guide wheels, balance beams, and connecting rods of CAT D6D/D6E/D6H bulldozers and 953/963 tracked loaders. It is used to withstand radial loads and low-speed oscillations, and is compatible with grease lubrication systems to ensure wear resistance and stable operation of the hinged parts. Key information is as follows:

Key Technical Parameters
Item Details
Part Model: CAT 7U-7345 (7U7345) Straight Steel Bushing, suitable for heavy-duty hinged parts, with lubrication groove + oil filling hole
Core Material: 40Cr alloy structural steel, integrally quenched and tempered (surface HRC 52–56, core HRC 28–32), surface anodized black for rust prevention, inner wall rolled hardened (Ra≤0.8 μm)
Key Dimensions: Inner diameter 50 mm, outer diameter 60 mm, length 60 mm mm diameter, 5 mm wall thickness, 1×45° chamfer at both ends, 4 mm diameter radial oil injection hole, 3 mm width and 1 mm depth axial lubrication groove. Weight: Approx. 0.42 kg. Compatible with CAT D6D/D6E/D6H bulldozers, 953/963 tracked loaders, 950G/966G loaders, etc., used for guide wheel brackets, balance beam hinge points, and connecting rod to frame hinges. Lubrication method: Grease lubrication (compatible with NLGI Grade 2 lithium-based grease). The oil injection hole matches the lubrication groove to ensure uniform oil film coverage of the contact surface. Core functions and structural features: Heavy-duty compatibility: 40Cr material with a yield strength ≥800 MPa, capable of withstanding large loads and impacts at bulldozer and loader hinge points, preventing deformation and breakage, suitable for heavy-duty bulldozing and loading conditions.

Wear-resistant and anti-seize: High surface hardness and inner wall rolling treatment reduce the coefficient of friction, preventing seizing with the pin, suitable for harsh environments such as construction sites with dust and mud, extending service life.

High-efficiency lubrication: Axial lubrication groove + radial oil injection hole design, after grease injection, a stable oil film is quickly formed, reducing friction and wear, and reducing the risk of abnormal noise and jamming at the hinge.

Easy assembly: The straight cylindrical structure is compatible with stepless seat holes, and the chamfered ends facilitate press-fitting. After press-fitting, it fits tightly with the seat hole, with precise positioning and no loosening.

Installation and maintenance points:
Installation specifications: Clean the seat hole and pin, removing burrs, iron filings, and oil. Seat hole diameter tolerance H7 (60 mm + 0.03 mm), roundness ≤ 0.015 mm, surface roughness Ra ≤ 1.6 μm.

Cold pressing assembly is used, with pressing force controlled at 4–5 tons, ensuring the bushing end face is flush and not tilted. The inner diameter shrinkage after press-fitting is ≤ 0.04 mm.

After assembly, check that the pin rotates freely without jamming, and that the radial clearance is controlled within 0.06–0.12 mm to avoid uneven wear caused by abnormal clearance.

Maintenance Recommendations: Every 200–300 working hours, add NLGI Grade 2 lithium-based grease until it overflows to ensure adequate lubrication.

Every 800–1000 working hours, check the bushing for looseness, outer diameter wear >0.1 mm, surface peeling, or cracks. Replace immediately if any problems are found.

When replacing, prioritize original parts or high-wear-resistant replacements to avoid premature failure caused by ordinary steel bushings, which could affect the normal operation of the equipment.