Overview
The ZF 4644.311.079 INPUT GEAR is a critical power-transfer component engineered specifically for the WG 181 series transmission. This OEM genuine part serves as the primary interface between the engine output and the transmission’s planetary gearset, converting rotational force into controlled torque distribution. As the first gear in the drivetrain sequence, the 4644.311.079 input gear directly engages with the TRANSMISSION HOUSING to ensure precise alignment and minimal backlash. Manufactured from case-hardened alloy steel, this SKU 4644.311.079 component withstands extreme shear stresses while maintaining dimensional stability under heavy-duty industrial loads.
Symptoms of Failure
- Audible gear whine during acceleration: A high-pitched noise from the transmission bell housing often indicates worn input gear teeth, particularly when the HOUSING alignment shifts due to bearing wear.
- Oil leaks near the input shaft seal: Degraded gear splines can cause vibration that compromises the THREADED BUSH seal surface, leading to fluid seepage.
- Hard shifting or gear slipping: When the input gear’s helical teeth lose their hardened surface layer, engagement with the countershaft becomes inconsistent, causing delayed or missed shifts.
- Metallic debris in transmission fluid: Flaking from the gear’s root fillet area contaminates the oil, often requiring replacement of the TYPE PLATE identification tag during service.
Technical Specifications
| Parameter | Value |
|---|---|
| Part Number | 4644.311.079 |
| Gear Type | Helical input gear, 18 teeth |
| Material | 20MnCr5 case-hardened steel |
| Hardness | 58-62 HRC (case depth 0.8-1.2mm) |
| Weight | 2.45 kg (5.4 lbs) |
| OEM Reference | ZF 4644.311.079 |
| Torque Capacity | 1,850 Nm peak |
| Mounting | Press-fit with keyway |
Compatibility
This input gear is validated for the ZF WG 181 series, including WG180, WG181, and WG200 variants. It also fits select WG150 and WG220 models when used with the correct GROOVED STUD kit. Always verify housing compatibility with your specific transmission serial number, as the COVER PLATE thickness may vary between series. For WG181 rebuilds, this gear pairs with the HEXAGON SCREW set and SET SCREW for secure retention. The SEALING RING and FIXING PLATE are also recommended for concurrent replacement.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4644101047 | TRANSMISSION HOUSING | Encloses gearset and supports bearings |
| 4644301380 | HOUSING | Intermediate casing for input shaft |
| 4644301189 | THREADED BUSH | Seal carrier and alignment guide |
| 0730365067 | TYPE PLATE | Identification tag for transmission series |
| 0631311009 | GROOVED STUD | Locating pin for housing alignment |
| 4644301161 | COVER PLATE | Seals input gear access port |
| 0636100621 | HEXAGON SCREW | Fastener for gear retention |
| 0631610020 | SET SCREW | Locks gear to shaft |
| 0634801098 | SEALING RING | Prevents oil bypass at input shaft |
| 4644301117 | FIXING PLATE | Secures bearing preload |
ZF 4644.311.079 INPUT GEAR – Gear RFQ Support
Use ZF 4644.311.079 INPUT GEAR as the reference when requesting gear support. Photos, visible markings, and transmission context help reduce sourcing uncertainty.
Part-Number Summary
Use ZF number 4644.311.079 when sending your RFQ. PartsZF can review dotted, spaced, and compact number formats against the available product and documentation records.
Application Context
- Illustration section: POWER TAKE OFF
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 | 4644.311.079 |
|---|---|
| Normalized SKU | 4644311079 |
| Part name | INPUT 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
