CAT 393-2894 Piston Rod Bearing

CAT 393-2894 is a Caterpillar single-row tapered roller bearing (inner ring/taper sleeve only), suitable for heavy-duty shaft end support in transmission systems such as gearboxes and final drives. It can withstand radial and unidirectional axial combined loads and is suitable for high-vibration and continuous operation conditions of medium and large excavators and loaders. It features high load capacity, wear resistance and impact resistance characteristics of Cat® Parts. The following is structured technical and application information:

Core Technical Parameters

Item Details
Basic Attributes
Model 393-2894, type is single-row tapered roller bearing (tapered sleeve), material 52100 bearing steel (quenched + tempered, hardness HRC 60-64), single weight approximately 2.1 kg, operating temperature -40℃ to +120℃, load type is radial load + unidirectional axial load, lubrication method is oil lubrication (recommended Cat DEO-ULS 15W-40 machine oil), design life ≥15000 hours (normal operating conditions)

Key Dimensions
Inner ring inner diameter 127 mm (5 inches, tolerance 0/-0.018 mm), inner ring width 46.8 mm (1.8425 inches, tolerance 0/-0.12 mm), rolling element diameter 15.875 mm, raceway cone angle 18°, inner ring large end diameter 165 mm, inner ring small end diameter 132 mm, surface roughness Ra≤0.4 μm, end face runout≤0.02 mm, inner ring radial runout≤0.015 mm
Compatible Models and Parts: Compatible with Cat 336D2L/349D2 excavators (C9.3 engine transmission output shaft), 966M loaders (transfer case input shaft), D8T bulldozers (final drive), with matching 393-2895 outer ring (cup sleeve), 5P-8353 seal ring, 3B-8489 grease fitting, 1J-6472 retaining ring (Cat® Parts)
Rated Load: Radial rated dynamic load Cr=220 kN, radial rated static load Cor=380 kN, allowable axial load ≤100 kN, allowable linear velocity ≤4.5 m/s (oil lubrication), limiting speed 2800 rpm (continuous operation), impact load ≥150 kN, ultimate pressure ≥420 kN MPa
Structural and Performance Advantages

The 52100 bearing steel is quenched and tempered, achieving a balance between raceway hardness and core toughness. This makes it suitable for high-frequency operation and complex loads in transmission systems, reducing the risk of fatigue spalling.

The single-row tapered roller structure can simultaneously withstand radial and unidirectional axial loads. Uniform contact between the raceway and rollers ensures high transmission efficiency, with operating noise ≤68 dB (1500 rpm).

The integral stamped cage guides the rollers to stable operation, preventing roller skew and improving high-speed bearing stability, making it suitable for continuous operation.

Installation and Maintenance Points
Before installation, clean the inner ring, outer ring, and mounting journal. Check for cracks, rust, and deformation. Measure the inner ring inner diameter (127 mm) and journal dimensions, ensuring an interference fit of 0.012-0.03 mm.

The inner ring is installed using a heat-fitting method (heating temperature 80-100℃, holding for 25 minutes). A special tool is used to press the inner ring into place, and striking the inner ring raceway surface is strictly prohibited. After installation, check for smooth rotation; there should be no jamming or abnormal noise, and axial movement should be ≤0.05 mm.

Maintenance and Replacement: Check lubrication and wear condition every 2000 hours. If the inner ring raceway wear is >0.2 mm or fatigue spalling or cracks appear, replace it immediately. It is recommended to replace it simultaneously with the outer ring and sealing ring to ensure transmission accuracy and sealing effect.