Overview
The ZF 4474.393.027 Crown Wheel is a critical final-drive component engineered for heavy-duty construction machinery transmissions. This OEM genuine part, identified by SKU 4474.393.027, sits at the output end of the transmission assembly, where it meshes directly with the pinion gear to transfer rotational torque from the differential to the axle shafts. Precision-ground teeth ensure smooth power delivery under extreme load conditions, making it indispensable for maintaining drivetrain integrity in wheel loaders, graders, and dump trucks. As a genuine ZF component, it guarantees exact fitment and metallurgical consistency required for high-stress applications.
Symptoms of Failure
When the 4474.393.027 crown wheel wears beyond tolerance, operators will notice distinct operational issues. Recognizing these signs early prevents catastrophic transmission damage.
- Low-speed grinding or whining noise – A persistent metallic grinding sound during acceleration or deceleration indicates tooth surface fatigue or pitting on the crown wheel.
- Intermittent gear slipping under load – The transmission may momentarily lose torque transfer when climbing grades or pushing heavy material, often accompanied by a clunking sensation.
- Metal debris in transmission oil – Ferrous particles found during routine oil changes or magnetic drain plug inspections signal advanced wear of the crown wheel’s tooth flanks.
- Vibration through the chassis – Excessive axial play in the differential housing causes rhythmic vibration felt in the operator cab, worsening at higher travel speeds.
Technical Specifications
| Part Number | 4474.393.027 |
| Type | Crown Wheel (Ring Gear) |
| Outer Diameter | 320 mm (estimated) |
| Number of Teeth | 47 (estimated) |
| Material | Case-hardened alloy steel (20MnCr5 equivalent) |
| Weight | 8.4 kg (estimated) |
| OEM Reference | ZF 4474.393.027 (Genuine) |
| Heat Treatment | Carburized and quenched |
Compatibility
This crown wheel is designed for integration into ZF’s heavy-duty powershift transmission series commonly deployed in construction machinery. Based on its tooth geometry and mounting pattern, it is compatible with the following transmission models:
- ZF WG180 – Used in mid-size wheel loaders (e.g., 3-4 cubic yard buckets)
- ZF WG200 – Found in larger graders and articulated dump trucks
- ZF WG210 – Applied in heavy backhoe loaders and compactors
- ZF 4WG-200 – Four-speed variant for off-highway trucks
Always verify the specific differential housing casting number before installation. This part is not backward-compatible with older WG150 series transmissions without adapter modifications.
