CAT 078-3401 BEARING

CAT 078-3401 is a Caterpillar genuine single-row deep groove ball bearing, suitable for the hydraulic pilot valve assembly (such as the 078-0776 spool valve) and actuator shaft system of the fuel injection control module in 3044C/3054C engines, 306E/307E excavators, and 226B3/246B3 skid steer loaders. It supports the rotating valve spool/control shaft, absorbs radial loads, and provides low-friction rotation, ensuring precise and jam-free valve assembly operation. It is often used in conjunction with the 078-1844 locking collar and the 078-2642 retaining spring (Cat®…).

Core Parameters and Information

Item Details
Part Model: CAT 078-3401 (0783401) Bearing

Structure Type: Single-row deep groove ball bearing with stamped steel cage, double-sided non-contact rubber seals (2RS), radial clearance C3 grade

Material: Inner/outer rings and rolling elements are high-carbon chromium bearing steel (SAE 52100), cage is SPCC cold-rolled steel plate, seals are nitrile rubber (NBR)

Key Dimensions: Inner diameter 15 mm, outer diameter 32 mm, width 9 mm, chamfer 0.3 mm, seal thickness 1.2 mm

Performance Parameters: Rated dynamic load 7.2 kN, rated static load 3.5 kN, grease-lubricated limiting speed 10000 rpm, operating temperature -40℃ to +120℃, rated life ≥5000 hours (1000 rpm condition)

Compatibility Standard: Complies with ISO 60049-1 (GB/T 307.1), compatible with 078-0776 spool valve, 078-1844 locking collar, and 078-2642 retaining spring.

Compatibility: Suitable for hydraulic pilot valve assemblies and fuel injection control modules of CAT 3044C/3054C engines, 306E/307E excavators, and 226B3/236B3/246B3 skid steer loaders.

Compatible Models and Application Scenarios:
Compatible Equipment: Hydraulic pilot valve assemblies and fuel injection control modules of CAT 3044C/3054C engines, 306E/307E mini excavators, and 226B3/236B3/246B3 skid steer loaders.

Application Scenarios: Supports the rotational movement of the valve core/control shaft, withstands radial loads, reduces frictional resistance, ensures rapid valve assembly response and precise positioning, and is suitable for medium-low pressure and medium-speed continuous operation.

Installation: Installed within the support seat hole of the valve core/control shaft. Dust and moisture-proof sealing rings on both sides secure the bearing. It works with the 078-1844 locking collar to fix the axial position and with the 078-2642 fixing spring to ensure stable mechanism reset and pressure regulation.

Installation and Maintenance Points: Clean the bearing and mounting hole. Check the bearing for rust, cracks, and cage damage. Ensure smooth rotation without jamming.

Use the cold-press method for installation. Apply even pressure to the inner ring using a special sleeve, avoiding impact loads. Ensure the bearing and seat hole coaxiality is ≤0.05 mm.

After installation, check that the axial runout is ≤0.1 mm, the radial clearance meets C3 grade (0.015-0.025 mm), and there is no abnormal noise during rotation.

Maintenance: Check the condition of the bearing every 2000 hours. Replace it immediately if rust, wear or excessive clearance is found. It is recommended to replace the seal at the same time to avoid secondary contamination.