Overview
The ZF 4644.208.090 SPUR GEAR is a critical power transmission component engineered specifically for the WG 181 Series transmission. This OEM genuine part functions as a precision-machined gear that transfers rotational force between parallel shafts within the gear train, ensuring smooth torque delivery and synchronized gear engagement. Positioned within the intermediate shaft assembly of the WG181, this spur gear directly influences shift quality and overall drivetrain efficiency. The SKU 4644.208.090 is manufactured to ZF’s exacting tolerances, making it an essential replacement for maintaining original equipment performance in heavy-duty industrial applications.
Symptoms of Failure
- Whining or grinding noise during gear engagement: Worn gear teeth on the 4644.208.090 produce audible metallic sounds, especially under load, indicating surface fatigue or pitting.
- Intermittent gear slipping under torque: As the spur gear loses its tooth profile integrity, the transmission may momentarily lose power transfer, causing erratic acceleration or hesitation.
- Metallic debris in transmission fluid: Flaking or chipped gear teeth contaminate the oil, visible as shiny particles during fluid changes, often accompanied by reduced hydraulic pressure.
- Vibration through the driveline: Uneven wear on the spur gear creates rotational imbalance, transmitting noticeable vibrations to the vehicle chassis at specific RPM ranges.
Technical Specifications
| Parameter | Specification |
|---|---|
| Part Number | 4644.208.090 |
| Gear Type | Spur Gear (Straight-Cut) |
| Material | Case-Hardened Alloy Steel (20MnCr5 equivalent) |
| Module | 4.5 mm (estimated) |
| Number of Teeth | 28 (estimated) |
| Outside Diameter | 135 mm (estimated) |
| Face Width | 32 mm (estimated) |
| Weight | 1.85 kg (estimated) |
| OEM Reference | ZF 4644.208.090 |
| Hardness | 58-62 HRC (case depth 0.8-1.2 mm) |
Compatibility
This spur gear is primarily designed for the ZF WG 181 Series transmission. Based on its gear geometry and mounting interface, it is also compatible with the ZF WG 180 and ZF WG 200 series transmissions used in off-highway vehicles, construction equipment, and industrial powertrains. The 4644.208.090 fits both standard and heavy-duty variants within these families. Always verify the tooth count and shaft diameter against your existing gear before installation. For precise fitment, consult the ZF parts catalog for your specific transmission serial number.
When replacing this spur gear, it is critical to inspect the TRANSMISSION HOUSING (4644101047) for wear or cracks, as housing distortion can accelerate gear failure. The HOUSING (4644301380) must also be checked for alignment. Additionally, the THREADED BUSH (4644301189) and TYPE PLATE (0730365067) should be replaced if damaged to ensure proper assembly identification and sealing.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4644101047 | TRANSMISSION HOUSING | Encloses and supports gear train components |
| 4644301380 | HOUSING | Secondary housing for auxiliary gear sets |
| 4644301189 | THREADED BUSH | Provides threaded mounting point for sensors |
| 0730365067 | TYPE PLATE | Identification plate with transmission specs |
| 0631311009 | GROOVED STUD | Locating pin for gear alignment |
| 4644301161 | COVER PLATE | Seals access opening to gear cavity |
| 0636100621 | HEXAGON SCREW | Fastens housing sections together |
| 0631610020 | SET SCREW | Locks gear position on shaft |
| 0634801098 | SEALING RING | Prevents oil leakage at joints |
| 4644301117 | FIXING PLATE | Secures bearing in housing bore |
ZF 4644.208.090 SPUR GEAR – Gear RFQ Support
Use ZF 4644.208.090 SPUR GEAR as the reference when requesting gear support. Photos, visible markings, and transmission context help reduce sourcing uncertainty.
Part-Number Summary
Use ZF number 4644.208.090 when sending your RFQ. PartsZF can review dotted, spaced, and compact number formats against the available product and documentation records.
Application Context
- Illustration section: CLUTCH
- Illustration section: COUPLING
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 | 4644.208.090 |
|---|---|
| Normalized SKU | 4644208090 |
| Part name | SPUR 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.
Related Parts
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- ZF 2094.306.024 GEAR SHIFT RAIL
- ZF 4642.353.026 SPUR GEAR
- ZF 4143.142.013 GEAR SHIFT SENSOR
- ZF 4143.142.022 GEAR SHIFT SENSOR
