CAT 6J-0684 TRUNNION

CAT 6J-0684 is a Caterpillar genuine double-ear pin trunnion (core hinge component). The following is pure, accurate original factory information (no additional description) Cat®…:

Core Parameters and Information

Item Details
Part Model: CAT 6J-0684 (6J0684) Double-Ear Pin Trunnion

Part Type: Double ear + center pin integrated, used for cylinder/connecting rod hinges, transmitting loads and allowing oscillation

Material: 42CrMo alloy steel, tempered to HRC 30–35, ear hole/pin surface hardened to HRC 45–50

Key Dimensions: Ear inner diameter 50.00 mm (H7), pin diameter 50.00 mm (m6), total length 220.00 mm, ear thickness 25.00 mm

Structural Features: Solid one-piece construction, 2×45° chamfers at both ends of the pin, precision-bored ear hole, no oil holes/ Oil Tank
Surface Treatment: Phosphating + Rust-preventive Oil (Original Standard)
Match Clearance: Earring Hole and Pin Clearance: 0.030–0.050 mm
Operating Temperature: -40℃ ～ +120℃
Shear Strength: ≥ 800 MPa
Weight: 3.85 kg
Compatible Models and Assemblies:
Excavators: CAT 320D2, 323D2, 326D2 (Stick/Boom Cylinder Earring Hinge)
Loaders: CAT 950M, 966M (Dump/Lift Cylinder Trunnion)
Bulldozers: CAT D6N, D6T (Shovel/Tilting Cylinder Trunnion)
Matching Parts: 6J-0684 Trunnion, Bushing (e.g., 329-1380), Retaining Ring, Sealing Ring
Installation and Fitting Points:
Clean the earring hole/bushing, deburr and remove rust; roughness Ra≤0.8μm.

Press-fit the bushing in the cold state, gently tapping the shaft pin into place; do not strike it forcefully.

After installation, the clearance should be 0.030–0.050 mm, and the axial runout ≤0.05 mm.

Apply lithium-based grease before assembly.