CAT 1J-0581 Cap-Bearing

CAT 1J-0581 is a bearing cap for Caterpillar engines/transmission systems. It is compatible with the front crankshaft bearing of C13/C15 engines, the input shaft bearing of the 336D2 excavator rotary gearbox, and other parts. It is used to fix the bearing, seal against dust, and bear axial loads. It is often used in conjunction with 388-7494 bearings and O-rings to ensure the stable operation of the bearing system. The following is structured technical and application information:

Core Technical Parameters

Item Details
Basic Attributes
Model 1J-0581, Bearing Cover (Bearing Cap/End Cover), Material: 42CrMo alloy steel (tempered and quenched, hardness HB260-290, tensile strength ≥1000 MPa, wear-resistant and impact-resistant), Surface galvanized and passivated (corrosion resistant, salt spray test ≥96 hours), Operating temperature -40℃ to +150℃, Single weight approximately 2.8 kg, Suitable for bearing parts such as the front end of engine crankshaft and input shaft of rotary gearbox, used for fixing bearings, sealing against dust, bearing axial loads, and preventing bearing movement and contaminant intrusion.

Key Dimensions
Inner diameter 100 mm (tolerance 0/-0.020 mm), Outer diameter 140 mm (tolerance +0.020/0 mm), Total thickness 25 mm, Mounting stop diameter 120 mm (tolerance +0.015/0 mm), Stop depth 5 mm The bolt holes are 4 in number (16 mm in diameter, evenly distributed, center circle diameter 125 mm, bolt specification M16×1.5), and the locating pin holes are 2 in diameter (8 mm, symmetrically distributed). Coaxiality ≤ 0.02 mm, flatness ≤ 0.015 mm. Compatible models: Cat C13/C15 engine (crankshaft front bearing), 336D2 excavator (slewing gearbox input shaft bearing), 980M loader (gearbox output shaft bearing), D8T bulldozer (final drive input shaft bearing). Matching bearings: 388-7494 bearing, 1J-0582 O-ring (inner diameter 100 mm, wire diameter 3.5 mm).

Assembly fit: The stop and bearing housing should have a transition fit (clearance 0.005-0.015 mm). Bolt preload torque: 120-130 N・m (tightened evenly in 2-3 stages). The sealing surface should be coated with Cat 5P-0960. Apply a thin, uniform sealant (0.2-0.3 mm thick). After installation, axial movement should be ≤0.03 mm to ensure reliable bearing fixation and no leakage.

Installation and Maintenance Points:
Before installation, clean the bearing cap sealing surface, bearing housing stop, and bolt holes. Check for scratches, pores, and cracks. Measure the stop diameter and flatness to ensure the fit meets requirements. The locating pins must be intact to avoid misalignment.

When installing the O-ring, apply a small amount of hydraulic oil for lubrication to prevent scratches. After aligning the bearing cap with the locating pins, tighten the bolts evenly to avoid uneven loading that could cause deformation. The sealing surface must be free of impurities to prevent seal failure.

Maintenance and Replacement: Check bolt torque and sealing surface leakage every 1000 hours. If bolts become loose, the sealing surface leaks, or the bearing cap deforms, replace it immediately. It is recommended to replace the bearing and O-ring simultaneously to ensure sealing and fixation effectiveness.