CAT 532-9427 44mm Diameter Needle Bearing Inner Race

CAT 532-9427 is a Caterpillar genuine tapered roller bearing inner race, suitable for final drives, differentials, or wheel end bearings in various heavy machinery. It provides precise guidance and load transfer surface for the rollers, and is the core load-bearing component of the bearing, ensuring stable operation under high-speed, heavy-load conditions.

Core Technical Parameters

Item Details
Part Model: CAT 532-9427 Tapered Roller Bearing Inner Ring

Material: Bearing-grade high-carbon chromium alloy steel (e.g., SAE 52100), carburized and quenched, surface hardness HRC 60-64, good core toughness, fatigue resistance, wear resistance, suitable for heavy-duty impact conditions

Key Dimensions: Inner diameter approx. 165.10 mm, outer diameter approx. 200.02 mm, width approx. 36.51 mm, inner ring flange height adapts to corresponding roller diameter, chamfer radius r≈2.5 mm, adapts to standard tapered roller bearing assembly clearance

Compatible Models: Commonly used in Caterpillar 770G, 772G, 773F/G mining dump trucks, and some D-series bulldozers, 950M/962M loaders’ final drive or differential tapered roller bearing assemblies

Compatible Bearings: Usually compatible with CAT 5P-1949 These bearings, including their corresponding outer rings (CUP), are used together to form a complete tapered roller bearing, suitable for high-speed, heavy-load applications such as final drives and differentials.

Core Functions and Structure

Load Transfer and Guidance: The inner raceway provides a precise trajectory for the rollers, evenly transferring radial and axial loads to the journal, ensuring efficient bearing capacity and adapting to complex load conditions during equipment operation.

Wear Protection and Lifespan Guarantee: The high-hardness raceway surface reduces friction and wear between the rollers and the inner ring, while the carburized layer enhances fatigue resistance, extending the overall bearing life and reducing equipment downtime for maintenance.

Assembly Positioning Reference: The inner ring’s inner diameter and the journal have an interference fit, achieving precise bearing positioning on the shaft, preventing slippage or movement during operation, ensuring the coaxiality of the bearing and related components, and avoiding abnormal vibration and noise.

Installation and Maintenance Points
Installation Specifications: Before installation, clean the inner raceway and journal surface to remove oil, rust, and impurities; inspect the inner raceway for scratches, pitting, peeling, or other defects. Replace any damaged bearing immediately to prevent premature bearing failure.

The inner race is heated using a hot-fitting method (oil temperature 80-100℃). After the inner diameter expands, it is quickly fitted onto the journal. After cooling, a reliable interference fit is formed. Do not directly strike the inner race with a hammer to prevent raceway deformation or surface damage.

After the inner race is installed, check the fit with the journal to ensure there is no clearance. When installing the rollers and outer race, control the bearing preload, adjusting according to the machine manual. Avoid excessive preload leading to overheating, or insufficient preload causing impact wear.

Maintenance Recommendations: Check every 1500-2000 working hours: Use oil analysis or equipment vibration testing to determine the wear and peeling of the inner race raceway. If abnormal bearing temperature rise, increased vibration, or abnormal noise is detected, disassemble and inspect the inner race condition immediately.

Regularly replace the bearing grease/oil to ensure adequate lubrication and avoid dry friction between the raceway and rollers. Use extreme pressure lithium-based grease suitable for the operating conditions. For oil lubrication, control the oil level and cleanliness to prevent impurities from entering and accelerating inner race wear.