CAT 388-0807 Articulating Hitch Cap

CAT 388-0807 is a Caterpillar original articulated connector cover, compatible with the boom/rocker arm articulated pin end caps of Cat 972H/980H/980K loaders, D11T bulldozers, and other models. It is an integrated structure made of cast steel, with a sealing groove and mounting flange. Its core function is to protect the articulated pin, bearings, and lubrication channels, preventing dust, moisture, and debris from entering, while also providing axial positioning for the pin. The following are professional technical and application guidelines:

Core Technical Parameters (Professional Version)

Item Details Basic Attributes Model 388-0807, Type: Articulated Connector Cover (cast steel, with O-ring sealing groove and flange mounting hole), Compatible with Cat 972H/980H/980K loader boom lower articulated pin, D11T bulldozer track frame articulated shaft, 988H loader rocker arm articulated pin end, Material: ASTM A516 Grade 70 Carbon steel (tensile strength ≥485 MPa, yield strength ≥265 MPa), epoxy primer + topcoat (salt spray resistance ≥240 hours), outer diameter φ180 mm, inner diameter φ120 mm (compatible with pin diameter φ120 mm, tolerance h6), cover thickness 25 mm, flange diameter φ220 mm, flange bolt holes 8 (evenly distributed, hole diameter φ18 mm, compatible with M16 bolts), unit weight approximately 12.5 kg, operating temperature -40℃ to +120℃, sealing groove compatible with φ130 mm O-ring (material NBR, wire diameter 5.3 mm), rated axial positioning force ≥80 kN. Key dimensions: outer diameter tolerance ±0.15 mm, inner diameter tolerance H7 (0/+0.040 mm), thickness tolerance ±0.20 mm, flange flatness ≤0.15 mm, bolt hole position tolerance. φ0.25 mm, sealing groove depth 5.5 mm (tolerance +0.10/-0.05 mm), groove width 5.4 mm (tolerance +0.10/-0.05 mm), coaxiality of cover and pin ≤0.10 mm

Material and Manufacturing Process: ASTM A516 Grade 70 carbon steel sand casting, normalized (HB 143-179), flange end face precision milled (Ra≤1.6 μm), sealing groove CNC turned (Ra≤0.8 μm), surface electrostatic sprayed epoxy primer + polyurethane topcoat (film thickness 80-120 μm), mounting surface free of porosity, shrinkage, and other defects, sealing groove roughness Ra≤0.8 μm, interference fit with O-ring (interference 0.10-0.15 mm)

Compatible Models: Cat 972H/980H/980K loader boom lower hinge pin, D11T The core components of this product—the articulated shaft of a bulldozer track frame, the articulated pin end of a 988H loader rocker arm, and the articulation point of a 777D mining truck suspension system—are designed to protect the articulated pin and bearing, preventing dust, moisture, and gravel intrusion, ensuring no grease leakage, and providing axial positioning for the pin. It is suitable for heavy-duty and dusty working conditions.

Assembly Fit: It has a clearance fit with the pin (0.05-0.10 mm) and a contact fit with the flange face of the articulated ear plate (plane contact area ≥95%). After installation, it is tightened with M16×80 bolts (8.8 grade) with a torque of 180-200 N·m. The O-ring pre-compression is 20%-25%, and the axial movement after installation is ≤0.2 mm.

Installation and Maintenance Points: Before installation, clean the cover sealing groove, pin end face, and articulated ear plate flange face. Check the cover for cracks, deformation, and rust, and ensure the O-ring is undamaged. Measure the dimensions of the sealing groove to ensure they meet the requirements of the pin diameter.

During assembly, apply lithium-based grease (NLGI 2) to the sealing groove, insert the O-ring, align the cover with the flange hole, and tighten the M16 bolts diagonally and evenly to the specified torque. After installation, check for leaks, and use a feeler gauge to measure the gap between the cover and the ear plate; it should be ≤0.05 mm.

Maintenance Recommendations: Check the bolt torque and sealing condition every 1000 hours. If leaks, loose bolts, or cover deformation occur, immediately replace the O-ring or hinged connector cover to prevent wear on the pins and bearings.