CAT 538-6775 SLEEVE-SEM

CAT 538-6775 (5386775) is a CAT 538-6775 SEM sleeve, a steel positioning/support sleeve, suitable for hinged/rotating parts of chassis and working devices, used for pin guidance, clearance compensation, and component positioning. The following is precise information (no additional description):

Core Parameters and Information

Item Details
Part Model: CAT 538-6775 SEM Sleeve

Part Type: Steel positioning sleeve, suitable for positioning and supporting heavy-duty hinged/rotating parts

Material: 45# high-quality carbon structural steel, overall heat treatment (HRC 28–32), surface galvanized passivation

Key Dimensions: Inner diameter approx. 45.00 mm (1.772 in), outer diameter approx. 60.00 mm (2.362 in), length approx. 80.00 mm (3.150 in), with 45° assembly chamfers at both ends

Structural Features Thick-walled cylindrical shape, flangeless design, smooth inner hole, used for radial positioning and support of pins to prevent component misalignment.

Compatible Structures: Matches pins (such as 538-6776, 538-6777) and retaining rings (538-6778) for positioning and support in boom/stick articulations, connecting rods, chassis suspension, etc.

Suitable Working Conditions: Heavy load, frequent swinging/rotation, suitable for dusty and humid outdoor working environments.

Compatible Models:
CAT 329D/336D Excavators (boom/stick articulations, connecting rods)
CAT 980M/982M Wheel Loaders (working device connecting rods, steering knuckles)
CAT D7E/D7F Bulldozers (track frames, working device articulations)
CAT 444F2/450F2 Backhoe Loaders (frame/working device articulation points)
Installation and Fitting Points: Clearance fit with pins, standard radial clearance. 0.025–0.040 mm, ensuring smooth and unobstructed rotation.

The sleeve has a transition fit with the mounting seat hole (clearance or interference 0–0.020 mm). It should be cold-pressed using a dedicated press-fit tool; striking the sleeve body is prohibited.

Before installation, clean the journal and seat hole to remove burrs, rust, and impurities. Pre-install the seals and retaining rings to ensure reliable axial positioning.

Axial positioning is achieved using the retaining ring/step to prevent movement. After installation, check for smooth rotation, no abnormal noise, no axial movement, and unobstructed lubrication channels.

Add the specified grease according to the machine manual. After initial lubrication, replenish grease every 500 working hours.

Maintenance and Replacement Instructions

Check the sleeve wear, inner bore ovality, and axial clearance every 500–700 working hours. Replace the sleeve if wear exceeds 0.15 mm or ovality exceeds 0.10 mm.

The use of non-standard sleeves is strictly prohibited to avoid abnormal wear of the pins and mounting bases, which may lead to hinge failure or component damage.