CAT 128-1049 Cylindrical Roller Bearing

CAT 128-1049 is a single-row tapered roller bearing (including inner ring/outer ring/rollers/cage) used by Caterpillar for gearboxes and drive axles in mini excavators and loaders. It is compatible with Cat 305.5/306/307 models and is used to support the input shaft/differential shaft, withstand radial and unidirectional axial heavy loads, and ensure smooth and efficient operation of the transmission system. The following is structured technical and application information:

Core Technical Parameters

Item Details
Basic Attributes
Model 128-1049, Type: Single-row tapered roller bearing, Material: High-carbon chromium bearing steel (chromium content 1.5-1.6%), Hardness after quenching and tempering: HRC60-64, Single weight: Approximately 0.72 kg, Operating temperature: -30℃ to +120℃, Lubrication method: Oil lubrication (recommended SAE 80W-90 gear oil), Design life: ≥8000 hours (normal operating conditions)

Key Dimensions
Inner diameter: 70.0 mm (tolerance 0/+0.018 mm), Outer diameter: 125.0 mm (tolerance 0/-0.015 mm), Width: 31.0 mm (tolerance ±0.10 mm), Raceway angle: 12°, Number of rollers: 14, Roller diameter: 14.0 mm, Cage material: Stamped steel plate, Interference with shaft: 0.01-0.02 mm mm, clearance with bearing housing 0.02-0.03 mm, radial runout ≤0.03 mm
Compatible Models and Applications: Compatible with Cat 305.5E2, 306E2, 307E2 and other small excavators, as well as some Cat 906H/907H loaders. Used in the gearbox input shaft and drive axle differential shaft support areas. Suitable for low-speed, heavy-load, and frequent impact load transmission conditions. Can withstand radial load and unidirectional axial load simultaneously.
Performance Parameters: Rated dynamic radial load 95 kN, rated static radial load 130 kN, rated axial load 42 kN, limiting speed 1800 rpm (oil lubrication), impact load capacity ≥60 kN, wear resistance conforms to ISO 281 standard, corrosion resistance reaches ISO 9227 neutral salt spray test 24. No obvious rust within hours.

Structural and Performance Advantages: The tapered roller structure can simultaneously withstand radial and unidirectional axial loads, adapting to complex stress scenarios in transmission systems, effectively suppressing shaft movement and improving transmission stability.

High-carbon chromium bearing steel undergoes professional heat treatment, resulting in high precision raceways and rollers, excellent wear resistance and fatigue resistance, suitable for harsh working conditions in engineering machinery, and reducing the risk of early failure.

The integrated stamped steel plate cage design ensures precise roller positioning, smooth operation, reduced noise and vibration, improved transmission efficiency, and extended component lifespan.

Installation and Maintenance Points: Before installation, clean the journal, bearing housing, and bearing surface, checking for cracks and burrs; install the inner ring using the hot fitting method (oil temperature 80-90℃), the outer ring and bearing housing have a transition fit, and are installed using the press-fit method; do not forcefully hammer and damage the raceway; after installation, adjust the axial clearance to 0.03-0.05 mm, ensuring smooth and unobstructed rotation.

After installation, ensure the gearbox/drive axle oil level is within specifications and the oil temperature does not exceed 85℃. During the initial operation period (first 50 hours), regularly check the bearing temperature and for any abnormal noises; address any issues promptly.

Maintenance: Check bearing wear and clearance every 1500 hours. If pitting, peeling, or clearance exceeding 0.15 mm is observed on the raceway, replace the entire set immediately (do not mix different models of parts). During replacement, adjust the axial clearance according to original factory specifications to ensure operational accuracy.