Overview
The ZF 4644.311.080 IDLER GEAR is a critical component within the WG 181 Series transmission, serving as a torque distribution intermediary between the input shaft and the main drive gear cluster. This OEM genuine part ensures precise rotational synchronization and load sharing across the gear train, directly influencing shift quality and power delivery. The SKU 4644.311.080 is engineered to exact ZF tolerances, reducing parasitic drag and minimizing vibration in heavy-duty industrial applications. When installed alongside the 4644101047 TRANSMISSION HOUSING, this idler gear maintains proper gear mesh alignment, preventing premature wear on adjacent components.
Symptoms of Failure
- Whining or howling noise during acceleration: A worn 4644.311.080 idler gear produces a distinct high-pitched metallic sound, especially under load, indicating pitting or tooth face degradation.
- Intermittent gear slippage in mid-range RPM: When the idler gear’s bearing surface deteriorates, torque transfer becomes inconsistent, causing the transmission to momentarily lose drive engagement between 1200-1800 RPM.
- Metallic debris in transmission fluid: Flaking from the idler gear’s hardened surface contaminates the oil, often visible as silver particles during routine fluid changes, signaling imminent gear failure.
- Increased operating temperature: Excessive friction from a failing idler gear generates localized heat, detectable through elevated transmission sump temperatures beyond normal operating ranges.
Technical Specifications
| Parameter | Value |
|---|---|
| Part Number | 4644.311.080 |
| OEM Reference | ZF WG181 Series |
| Material | Case-hardened alloy steel (20MnCr5 equivalent) |
| Outer Diameter | 108 mm (estimated) |
| Tooth Count | 34 teeth (helical) |
| Bore Diameter | 32 mm |
| Weight | 1.45 kg |
| Hardness | 58-62 HRC (surface) |
| Surface Finish | Ground, shot-peened |
Compatibility
This idler gear is specifically designed for the ZF WG 181 transmission series, but it also cross-fits select models in the WG180 and WG200 families due to shared gear train architecture. It is commonly found in WG181-2, WG181-3, and WG181-4 variants used in municipal trucks, construction loaders, and agricultural tractors. For proper installation, verify that the 4644301380 HOUSING is free of cracks and the 4644301189 THREADED BUSH is torqued to factory specifications. Always replace the 0730365067 TYPE PLATE during rebuilds to ensure correct identification of updated gear ratios.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4644101047 | TRANSMISSION HOUSING | Encloses and aligns all gear train components |
| 4644301380 | HOUSING | Supports idler gear shaft and bearing assembly |
| 4644301189 | THREADED BUSH | Secures idler gear shaft to housing |
| 0730365067 | TYPE PLATE | Identifies transmission model and gear ratios |
| 0631311009 | GROOVED STUD | Positions and locks idler gear shaft |
| 4644301161 | COVER PLATE | Seals idler gear access port |
| 0636100621 | HEXAGON SCREW | Fastens cover plate and housing sections |
| 0631610020 | SET SCREW | Adjusts idler gear end-play clearance |
| 0634801098 | SEALING RING | Prevents oil leakage at shaft interfaces |
| 4644301117 | FIXING PLATE | Retains idler gear axial position |
ZF 4644.311.080 IDLER GEAR – Gear RFQ Support
ZF 4644.311.080 IDLER 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 4644.311.080 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 | 4644.311.080 |
|---|---|
| Normalized SKU | 4644311080 |
| Part name | IDLER 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
- ZF 4661.302.010 GEAR
- 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
