CAT 078-3392 BEARING

CAT 078-3392 is a Caterpillar original single-row radial ball bearing, suitable for use in the hydraulic pilot valve assemblies (such as the 078-0776 spool valve) and actuator shafts of the fuel injection control module in Caterpillar 306E/307E excavators, 226B3/246B3 skid steer loaders, and 3044C/3054C engines. 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 to improve mechanism stability and response speed.

Core Parameters and Information

Item Details
Part Model: CAT 078-3392 (0783392) Bearing

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

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

Key Dimensions: Inner diameter 12 mm, outer diameter 28 mm, width 8 mm, chamfer 0.3 mm, seal thickness 1.2 mm

Performance Parameters: Rated dynamic load 5.8 kN, rated static load 2.7 kN, limiting speed (grease lubrication) 12000 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 (such as 078-0776 spool valves) 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, sealed on both sides for dust and moisture protection. 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 for rust, cracks, and cage damage, and ensure smooth rotation without jamming.

Use the cold-pressing method for installation, applying even pressure to the inner ring with a special sleeve to avoid impact loads and 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 the C3 standard (0.012-0.020 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.