Overview
The ZF 0631.501.430 FITTED KEY is a precision-machined locating component engineered specifically for the WG 65 series transmission assembly. This OEM genuine part ensures correct rotational alignment between the transmission housing and internal shaft assemblies, preventing unwanted movement under high torque loads. The SKU 0631.501.430 is installed as a positive-lock interface within the gear train, working in concert with the TRANSMISSION HOUSING (4616101059) to maintain structural integrity. Without this fitted key, the entire drivetrain would lack the necessary indexing for smooth power transfer.
Symptoms of Failure
- Intermittent gear slippage under load: A worn 0631.501.430 key allows the shaft to rotate slightly within its bore, causing erratic engagement and power loss during acceleration.
- Abnormal vibration at the transmission bell housing: When the fitted key shears or deforms, rotational imbalance occurs, producing a low-frequency rumble that intensifies with RPM.
- Oil seepage near the shaft seal area: Misalignment from a failing key distorts the seal surface, leading to gradual fluid loss around the output shaft.
- Hard shifting or gear clash: Loss of precise timing between the input shaft and planetary gearset results in delayed or grinding gear changes.
Technical Specifications
| Parameter | Value |
|---|---|
| Part Number | 0631.501.430 |
| Material | Case-hardened alloy steel (DIN 1.7131) |
| Overall Length | 42.0 mm |
| Width | 12.0 mm |
| Height | 8.0 mm |
| Weight | 0.032 kg |
| OEM Reference | ZF 0631.501.430 |
| Hardness | HRC 48-52 |
Compatibility
This fitted key is a direct replacement for the ZF WG 65 series transmission. It is also compatible with the following ZF models that share the same shaft-key interface: WG180, WG200, WG210, and WG250. Always verify the keyway dimensions in your specific housing before installation. For proper assembly, this part must be torqued in sequence with the HEXAGON SCREW (0636011038), the HEXAGON SCREW (0636011118), and the HEXAGON SCREW (0636016015) to ensure uniform clamping force.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4616101059 | TRANSMISSION HOUSING | Main structural casing for gear assembly |
| 0636011038 | HEXAGON SCREW | Fastener for housing cover |
| 0636011118 | HEXAGON SCREW | Fastener for bearing retainer |
| 0636016015 | HEXAGON SCREW | Fastener for output flange |
| 0631306085 | CYLINDRICAL PIN | Alignment dowel for housing halves |
| 0634313118 | O-RING | Static seal for oil passages |
| 0636304019 | SCREW PLUG | Sealing plug for inspection port |
| 0634801152 | SEALING RING | Dynamic seal for rotating shaft |
| 0732611049 | FILTER INSERT | Hydraulic fluid filtration element |
| 0634303718 | O-RING | Seal for valve body cover |
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