CAT 7U-7297 BEARING

CAT 7U-7297 (7U7297) is a Caterpillar single-row tapered roller bearing assembly, suitable for heavy-duty transmission components such as drive axle differentials and gearbox axles in CAT loaders and bulldozers. It is used to withstand combined radial and bidirectional axial loads. The following is the core technical information:

Core Technical Parameters
Item Details
Part Model: CAT 7U-7297 (7U7297) Single-row tapered roller bearing assembly (including inner ring/outer ring/rollers/cage, suitable for heavy-duty transmission conditions)

Core Materials: Inner ring/outer ring: SAE 52100 bearing-grade alloy carburized steel, carburized and quenched, hardened layer depth 1.0–1.4 mm, hardness HRC 60–64; Rollers: Chromium steel (GCr15), surface Ra≤0.4 μm; Cage: Stamped low-carbon steel, anti-roller misalignment

Key Dimensions: Inner diameter 85 mm, outer diameter 140 mm mm in diameter, 38 mm in width, 10° raceway taper angle, suitable for journals 85 mm (tolerance h6, 0–-0.030 mm), 1:12 taper with outer ring, 0.010–0.025 mm interference fit. Weight: Approx. 2.8 kg. Compatible with CAT 966M/966K loaders (drive axle differential), D9R/D9T bulldozers (gearbox axle 2), and 950M loaders (final drive input shaft). Used for heavy-duty transmission systems, suitable for radial + bidirectional axial combined load conditions. Operating tolerances: Dynamic radial load 180 kN, limiting speed 3200 rpm, operating temperature -30℃ to +150℃, compatible with extreme pressure lithium-based grease (NLGI 2). Core functions and structural features: Separable structure: The inner and outer rings are separable, facilitating installation, disassembly, and maintenance, suitable for transmission parts with limited space.

Conical Load Distribution: A 10° raceway cone angle evenly distributes radial and axial loads, reducing local stress concentration and improving fatigue resistance.

Interference Fit Fixing: The inner diameter and journal are interference-fitted by 0.010–0.025 mm, ensuring torque transmission without slippage, guaranteeing transmission accuracy, and reducing vibration and noise.

High-Precision Cage: The stamped steel cage has uniform spacing and precise roller positioning, suppressing misalignment and extending bearing assembly life.

Installation and Maintenance Points
Installation Specifications: Clean the journal and bearing housing. Journal surface Ra≤0.8 μm, tolerance h6 (0–-0.030 mm), hardness HRC≥58; bearing housing tolerance H7, surface free of scratches and burrs.

Heat the inner ring (≤120℃) before assembly, using a sleeve to press against the inner ring end face and apply force evenly to ensure tight contact with the shaft shoulder; cold install the outer ring, adjusting the preload to the value in the model manual (e.g., 80–100 N・m for the 966M differential). Apply extreme pressure lithium-based grease, filling the bearing to 1/3–1/2 of its internal space to prevent heat buildup.

Maintenance Recommendations: Every 1000 operating hours, check for raceway wear, spalling, and burning. Replace immediately if the inner diameter clearance is >0.05 mm. Simultaneously check journal wear (>0.02 mm requires repair).

When replacing, prioritize genuine parts to avoid confusion with similar models such as 7U-7298.

Simultaneously check the lubrication channels, clean impurities, and prevent abnormal wear.