CAT M318C Compatible Excavator Swing Gearbox with Multi-stage Planetary Gear and Heavy-Duty Bearings
This swing reduction gearbox is a core power transmission component for CAT M318C wheeled excavators, built with a multi-stage planetary gear system and heavy-duty internal parts to deliver stable, high-torque rotation for the upper structure.
- Swing Input Shaft: Connects directly to the swing motor, transferring hydraulic power into the gearbox with precision splines for zero-slip power delivery.
- Planetary Gear Set (Multi-stage): Includes sun gears, planetary gears, and planetary carriers. The high-strength alloy gears provide large torque multiplication and smooth speed reduction, enabling precise and stable upper-structure rotation.
- Internal Gear Ring: A rigid, precision-machined ring gear that meshes with planetary gears, forming the core reduction mechanism and bearing heavy radial and axial loads.
- Swing Drive Pinion (155-0867): The final output gear that meshes with the swing bearing, converting gearbox torque into controlled rotational motion of the excavator's upper frame.
- Heavy-Duty Bearings: Tapered roller and cylindrical roller bearings support high radial/axial loads, ensuring low friction, long service life, and stable operation under continuous heavy-duty use.
- Swing Brake Assembly: Built-in multi-disc brake components (brake discs, plates, and pistons) provide reliable parking and emergency braking, preventing uncontrolled swinging.
- Seals & Gaskets: High-performance oil seals and gaskets prevent hydraulic oil leakage and block dust, mud, and water ingress, maintaining internal lubrication and component cleanliness.
- Gearbox Housing: A robust cast housing that encloses and protects all internal parts, with precise mounting interfaces for stable integration with the excavator's frame.
All parts are manufactured to CAT original specifications, using wear-resistant alloy steel and precision machining. They ensure reliable operation in construction, municipal engineering, and material handling scenarios, supporting smooth, accurate, and durable swing performance for the CAT M318C wheeled excavator.
| Product Name | Excavator Swing Shaft |
| Place of Origin | Guangzhou China |
| Compatible Models | M318C/M320M322D |
| Part Numbers | 155-0856 |
| Shipping Methods | By Sea, By Air or By Express |
| Delivery Time | Within 2 days after receiving payment |




| # | Part No. | Description | Qty |
|---|---|---|---|
| 1 | 155-0856 | [1] SHAFT | 1 |
| 2 | 155-0857 | [3] GEAR-PLANETARY (33-TEETH) | 3 |
| 3 | 155-0858 | [1] CARRIER | 1 |
| 4 | 155-0824 | [3] PIN | 3 |
| 5 | 082-3084 | [6] WASHER | 6 |
| 6 | 082-3085 | [6] WASHER | 6 |
| 7 | 132-4292 | [63] BEARING AS-NEEDLE | 63 |
| 8 | 095-0919 | [3] RING-RETAINING | 3 |
| 9 | 155-0864 | [1] HOUSING AS-SWING | 1 |
| 10 | 155-0865 | [1] SEAL-LIP TYPE | 1 |
| 11 | 155-0866 | [1] SEAL | 1 |
| 12 | 155-0867 | [1] PINION | 1 |
| 13 | 155-0868 | [1] WASHER (100X169X2-MM THK) | 1 |
| 14 | 155-0869 | [1] BEARING AS-ROLLER | 1 |
| 15 | 155-0870 | [1] BEARING AS-ROLLER | 1 |
| 16 | 179-3152 | [2] NUT-SLOTTED | 2 |
| 17 | 155-0872 | [1] RING | 1 |
| 19 | 155-0874 | [1] CARRIER-PLANETARY | 1 |
| 20 | 155-0875 | [4] GEAR-PLANETARY (32-TEETH) | 4 |
| 21 | 155-0876 | [4] BEARING AS-ROLLER | 4 |
| 22 | 9X-0656 | [4] RING | 4 |
| 23 | 8U-5005 | [3] SHIM (1-MM THK) | 3 |
| 24 | 095-0928 | [1] RING-RETAINING | 1 |
| 25 | 121-8088 | [2] BALL BEARING | 2 |
| 26 | 155-0877 | [1] GEAR-SUN (19-TEETH) | 1 |
| 27 | 098-2982B | [4] SHIM (1.5-MM THK) | 4 |
| 28 | 110-4737 | [2] RING-RETAINING | 2 |
| 29 | 155-0878 | [1] HOUSING-BRAKE | 1 |
| 30 | 155-0849 | [1] ORIFICE | 1 |
| 31 | 8T-4139M | [4] BOLT (M12X1.75X30-MM) | 4 |
| 32 | 222-5793 | [1] SEAL-O-RING | 1 |
| 33 | 155-0850 | [1] PISTON | 1 |
| 34 | 155-0851 | [1] SEAL-LIP TYPE | 1 |
| 35 | 155-0852 | [1] SEAL-LIP TYPE | 1 |
| 36 | 179-3151 | [1] SPRING | 1 |
| 37 | 179-3154 | [1] SHIM (3.5-MM THK) | 1 |
| 38 | 132-4268 | [5] DISC-CLUTCH (1.7-MM THK) | 5 |
| 39 | 132-4262 | [6] DISC-CLUTCH (1.4-MM THK) | 6 |
| 40 | 132-4263 | [1] DISC-CLUTCH (1.2-MM THK) | 1 |
| 41 | 132-4265 | [1] DISC-CLUTCH (1.6-MM THK) | 1 |
| 42 | 132-4266 | [1] DISC-CLUTCH (1.8-MM THK) | 1 |
| 43 | 9X-6574 | [1] RING-RETAINING | 1 |
| 44 | 155-0855 | [1] SLEEVE | 1 |
| 45 | 8T-0707 | [1] RING-RETAINING (INTERNAL) | 1 |
| 46 | 222-5792 | [1] SEAL-O-RING | 1 |
| 47 | 197-6054 | [1] WASHER (63.6X70X0.5-MM THK) | 1 |
Our facility includes over 4000 square meters of three-dimensional warehouse space plus 2000 square meters of outdoor storage, ensuring adequate inventory levels and rapid response to customer requirements. Fast delivery is our competitive advantage.



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