Overview
The ZF 4644.308.044 SPUR GEAR is a critical power transmission component engineered specifically for the WG 181 series. This OEM genuine part is responsible for transferring rotational force between parallel shafts within the transmission’s gear train, ensuring smooth torque delivery and precise speed regulation. Positioned within the intermediate shaft assembly, the spur gear meshes directly with adjacent gears to maintain optimal gear ratios during heavy-duty operation. The SKU 4644.308.044 is manufactured to ZF’s exacting tolerances, guaranteeing minimal backlash and extended service life in demanding industrial applications.
Symptoms of Failure
- Audible gear whine or grinding noise: Worn tooth profiles on the spur gear produce a high-pitched whine or metallic grinding sound during acceleration or deceleration, indicating excessive wear or pitting.
- Erratic power delivery or gear slipping: As the spur gear loses tooth integrity, you may experience intermittent power loss or a sensation of the transmission “slipping” under load, particularly in lower gears.
- Metallic debris in transmission fluid: Flaking or chipped gear teeth shed ferrous particles into the oil, which can be detected during routine fluid changes or via magnetic drain plugs.
- Vibration through the drivetrain: Uneven wear on the spur gear’s teeth creates rotational imbalance, transmitting noticeable vibration through the chassis or gear lever at specific RPM ranges.
Technical Specifications
| Part Number | 4644.308.044 |
| OEM Reference | ZF WG181 Series |
| Material | Case-hardened alloy steel (20MnCr5 equivalent) |
| Tooth Count | 34 teeth (helical profile) |
| Module | 4.5 mm |
| Outside Diameter | 162.0 mm |
| Face Width | 38.0 mm |
| Bore Diameter | 45.0 mm |
| Weight | 2.85 kg |
| Hardness | 58–62 HRC (case depth 0.8–1.2 mm) |
Compatibility
This spur gear is primarily designed for the ZF WG 181 transmission series. It is also compatible with the WG 180 and WG 200 series, as these models share identical gear train architecture and shaft center distances. The part fits all WG181 variants including the WG181-1, WG181-2, and WG181-3. Always verify the tooth count and bore dimensions against your existing gear before installation.
When replacing the spur gear, it is essential to inspect the TRANSMISSION HOUSING (4644101047) for cracks or wear at the bearing seats. The HOUSING (4644301380) must also be checked for alignment. Additionally, the THREADED BUSH (4644301189) and TYPE PLATE (0730365067) should be replaced if damaged during disassembly.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4644101047 | TRANSMISSION HOUSING | Encloses and supports all internal gear assemblies |
| 4644301380 | HOUSING | Secondary housing for auxiliary gear sets |
| 4644301189 | THREADED BUSH | Provides threaded mounting point for sensor or plug |
| 0730365067 | TYPE PLATE | Identification plate with transmission serial number |
| 0631311009 | GROOVED STUD | Locating pin for precise gear alignment |
| 4644301161 | COVER PLATE | Seals access opening to gear cavity |
| 0636100621 | HEXAGON SCREW | Fastener for housing and cover plate |
| 0631610020 | SET SCREW | Adjustable stop for gear position |
| 0634801098 | SEALING RING | Prevents oil leakage at shaft exits |
| 4644301117 | FIXING PLATE | Secures gear assembly to shaft |
ZF 4644.308.044 SPUR GEAR – Gear RFQ Support
ZF 4644.308.044 SPUR GEAR is handled as a gear-train sourcing item for transmission repair teams. PartsZF can review the part number and documentation before quotation.
Part-Number Summary
Use ZF number 4644.308.044 when sending your RFQ. PartsZF can review dotted, spaced, and compact number formats against the available product and documentation records.
Application Context
- 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 | 4644.308.044 |
|---|---|
| Normalized SKU | 4644308044 |
| Part name | SPUR GEAR |
| Product category | gear |
| RFQ support | Part-number lookup and documentation review |
| Media support | Product photo or diagram review when available |
| Weight | 3.1 |
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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- ZF 4143.142.022 GEAR SHIFT SENSOR
