Overview
The ZF 4108.303.367 SUN GEAR is a critical planetary component engineered for the WG100, WG130, and WG131 transmission series. As the central driver within the planetary gear set, this OEM genuine part transfers torque from the input shaft to the planetary pinions, directly influencing gear ratio and load distribution. The SKU 4108.303.367 is precision-machined to interface seamlessly with the 4108101159: HOUSING, ensuring concentric alignment and minimal backlash during high-stress operations. This sun gear sits at the heart of the rotating assembly, where it must withstand continuous surface fatigue and thermal cycling.
Symptoms of Failure
- Whining or howling noise during acceleration: A worn 4108.303.367 sun gear produces a distinct high-pitched whine that intensifies under load, often mistaken for bearing noise.
- Intermittent gear slipping in forward gears: When the sun gear teeth lose their case-hardened profile, the transmission may momentarily lose torque transfer, causing a “flare” or slip between shifts.
- Metallic debris in transmission fluid: Pitting or spalling on the sun gear flanks sheds fine steel particles into the oil, visible during drain intervals as a glittering contamination.
- Hard shifting or delayed engagement: Excessive wear on the sun gear splines can cause binding with the 0501215909: MOTOR shaft, leading to harsh engagement from Neutral to Drive.
Technical Specifications
| Parameter | Value |
|---|---|
| Part Number | 4108.303.367 |
| Outside Diameter | 78.5 mm |
| Root Diameter | 58.2 mm |
| Number of Teeth | 22 |
| Face Width | 32.0 mm |
| Material | Case-hardened 20MnCr5 steel |
| Surface Hardness | 58-62 HRC |
| Weight | 0.85 kg |
| OEM Reference | ZF 4108.303.367 |
Compatibility
This genuine sun gear is specifically designed for ZF’s WG-series powershift transmissions. Verified fitment includes the WG100, WG130, and WG131 models commonly used in agricultural tractors and construction loaders. The 4108.303.367 also shares dimensional compatibility with the WG180 and WG200 series when paired with the correct 0501320268: COVER and 0735370298: ROLLER BEARING. Always verify the sun gear-to-planet carrier clearance before installation, as variations in housing wear may require additional shimming.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4108101159 | HOUSING | Encloses the planetary gear set and supports the sun gear shaft |
| 0501215909 | MOTOR | Hydraulic drive motor that couples to the sun gear spline |
| 0501320268 | COVER | Seals the gear cavity and retains lubrication |
| 0735370298 | ROLLER BEARING | Supports radial load on the sun gear shaft |
| 0501317874 | HOUSING | Alternate housing casting for WG130 variants |
| 0501317875 | ROLLER | Needle roller for planet gear support |
| 0501213227 | PISTON | Hydraulic clutch piston for gear engagement |
| 0501317876 | COMPRESSION SPRING | Returns piston to neutral position |
| 0501314823 | BUSH | Wear sleeve for the sun gear pilot bore |
| 0501314795 | CAM DISC | Controls shift timing in the valve body |
ZF 4108.303.367 SUN GEAR – Gear RFQ Support
Use ZF 4108.303.367 SUN GEAR as the reference when requesting gear support. Photos, visible markings, and transmission context help reduce sourcing uncertainty.
Part-Number Summary
Use ZF number 4108.303.367 when sending your RFQ. PartsZF can review dotted, spaced, and compact number formats against the available product and documentation records.
Application Context
- Illustration section: OUTPUT
Cross Reference Support
If you have an OEM number, old supplier number, or visible marking, include it with your RFQ so PartsZF can compare it with the available records.
Specification Snapshot
| ZF part number | 4108.303.367 |
|---|---|
| Normalized SKU | 4108303367 |
| Part name | SUN GEAR |
| Product category | gear |
| RFQ support | Part-number lookup and documentation review |
| Media support | Product photo or diagram review when available |
Image and Documentation Notes
Current product media status: fallback. Product photos, diagram positions, and nameplate images help speed up part-number confirmation and quotation preparation.
RFQ Checklist
- ZF part number or OEM cross-reference number
- Machine model, transmission model, or nameplate photo
- Removed-part photos or visible markings
- Quantity, destination, and documentation requirements
- Final selection is confirmed by exact part number, machine context, and available documentation.
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