CAT 8I-4407 BEARING

CAT 8I-4407 is a Caterpillar needle roller bearing, mainly used in steering knuckles, connecting rods, or gearbox input shafts of wheel loaders/excavators. It bears radial heavy loads and provides rotary guidance, and is compatible with models such as 950M/962M loaders and 320GC excavators, ensuring stable and efficient operation of the transmission and steering systems. The following is the core information:

Core Technical Parameters
Item Details
Part Model CAT 8I-4407 (8I4407) Needle Roller Bearing, no inner ring design, suitable for shaft diameter 38mm, used for radial support and rotary guidance under heavy-duty conditions Cat®…

Material Bearing steel (GCr15), carburized and quenched HRC 60-64, cage is stamped steel plate/engineering plastic, suitable for operating conditions from -40℃ to 120℃, resistant to mineral oil and grease corrosion

Key Dimensions Inner diameter 38mm, outer diameter 52mm, length 40mm, needle roller diameter 3mm, quantity 12 pieces, single weight approximately 0.18kg, suitable for mounting positions with shaft diameter 38mm and mounting hole diameter 52mm

Compatible Models CAT 950M/962M/972M loaders, 320GC/330GC excavators, 988K Suitable for mining loaders, 140M graders, etc., compatible with steering knuckles, connecting rods, gearbox input shafts, etc., working pressure ≤40MPa.

Performance Parameters: Radial rated dynamic load ≥52kN, radial rated static load ≥78kN, limiting speed 3000rpm, fit clearance 0.02-0.05mm, impact resistant, wear resistant, suitable for high-frequency reciprocating and rotating conditions.

Core Functions and Structural Features:

Heavy-duty radial support: Large needle roller contact area, suitable for steering knuckles, connecting rods, and other radially heavy-duty parts, withstanding instantaneous impact loads ≥100kN, ensuring stable shaft rotation without runout.

Compact and efficient: Inner ring-less design saves installation space, suitable for narrow installation positions, needle rollers directly contact the shaft, transmission efficiency ≥98%, reducing power loss.

Wear-resistant and fatigue-resistant: Bearing steel carburized and quenched + precision ground needle rollers, surface roughness Ra≤0.4μm, suitable for long-term high-frequency rotating conditions, service life ≥8000 working hours.

Installation and Fit: Interference fit installation (interference between mounting hole and bearing outer diameter 0.02-0.04mm), can be assembled by cold fitting (-20℃) or press fitting (pressure ≤5kN), no additional adjustment required.

Installation and Maintenance Points
Installation Specifications: Clean the mounting hole and shaft surface to remove oil, metal shavings, and burrs. Check the shaft roundness ≤0.02mm and surface hardness ≥HRC 50 to avoid damage from needle roller contact.

Use a special press to smoothly press the bearing into the mounting hole, ensuring the end face fits snugly against the mounting surface without tilting. After installation, check the shaft’s rotational flexibility for any jamming.

After installation, add lithium-based grease (filling amount 1/3-1/2 of the bearing’s internal space) to meet the lubrication needs of continuous rotation or intermittent operation.

Maintenance Recommendations: Check bearing wear every 3000 working hours. Replace immediately if needle rollers show pitting, cage deformation, or clearance ≥0.1mm to prevent accelerated shaft wear.

Simultaneously inspect the wear on the shaft surface. If the shaft diameter wear is ≥0.1mm, it must be replaced together with the 8I-4407 bearing to ensure the fit accuracy.