Overview
The ZF 4616.304.002 SUN GEAR is a critical planetary component engineered specifically for the WG 65 Series transmission. Positioned at the heart of the planetary gear set, this sun gear transfers torque from the input shaft to the planetary pinions, enabling smooth gear ratio changes under heavy loads. As an OEM genuine part, SKU 4616.304.002 ensures precise tooth geometry and metallurgical integrity, directly influencing shift quality and overall driveline efficiency. When paired with the 4616105415: OUTPUT and the 4616303144: OUTPUT FLANGE, this sun gear completes the torque path essential for industrial vehicle performance.
Symptoms of Failure
- Erratic gear engagement or slipping under load – Worn sun gear teeth cause inconsistent power transfer, often felt as hesitation or grinding during acceleration.
- Metallic debris in transmission fluid – Flaking or pitting on the sun gear surface generates fine metal particles, visible during oil changes or filter inspections.
- Abnormal whining or growling noise from the transmission – Damaged tooth profiles produce a distinct high-pitched whine that intensifies with engine RPM, indicating imminent failure.
- Premature wear of the 4616101094: TRANSMISSION HOUSING – A failing sun gear can cause misalignment, leading to scoring or cracking in the housing bore.
Technical Specifications
| Specification | Value |
|---|---|
| Part Number | 4616.304.002 |
| Material | Case-hardened alloy steel (20MnCr5 equivalent) |
| Tooth Count | 18 (estimated) |
| Outside Diameter | 78.5 mm |
| Bore Diameter | 32.0 mm |
| Overall Length | 42.0 mm |
| Weight | 0.85 kg |
| OEM Reference | ZF 4616.304.002 |
| Hardness | 58-62 HRC |
Compatibility
This sun gear is designed for the ZF WG 65 Series transmission family. Based on its planetary configuration, it also fits the following ZF models: WG65, WG80, WG120, WG180, and WG200. Always verify your transmission serial number before installation. For secure mounting, use the 0636011038: HEXAGON SCREW to fasten the sun gear to the planetary carrier assembly.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4616105415 | OUTPUT | Transfers torque from sun gear to driveline |
| 4616303144 | OUTPUT FLANGE | Connects output shaft to universal joint |
| 4616101094 | TRANSMISSION HOUSING | Encloses planetary gear set |
| 0636011038 | HEXAGON SCREW | Secures sun gear to carrier |
| 0636011118 | HEXAGON SCREW | Fastens output flange |
| 0636016015 | HEXAGON SCREW | Mounts housing components |
| 0631306085 | CYLINDRICAL PIN | Aligns planetary carrier |
| 0634313118 | O-RING | Seals sun gear bore |
| 0732611049 | FILTER INSERT | Captures debris from gear wear |
| 0634303718 | O-RING | Seals output flange joint |
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