Overview
The ZF 0631.501.213 FITTED KEY is a precision-machined locating component engineered specifically for the WG 65 Series transmission. This OEM genuine part ensures correct alignment and torque transfer between the gear shaft and the hub assembly within the planetary gear set. The SKU 0631.501.213 is installed directly into the 4616101059: TRANSMISSION HOUSING, where it prevents rotational slippage and maintains the structural integrity of the drivetrain. Without this fitted key, the transmission cannot maintain proper gear engagement under load.
Symptoms of Failure
- Intermittent gear slipping under heavy load: When the 0631.501.213 key wears or shears, the shaft loses positive engagement, causing the WG65 to momentarily lose torque transfer during acceleration or uphill operation.
- Metallic knocking or clunking from the transmission housing: A loose or broken fitted key allows the hub to shift slightly, producing a distinct metallic impact sound that intensifies with RPM changes.
- Oil contamination with fine metal particles: As the key surface degrades, microscopic steel fragments enter the lubrication system, often detected during routine oil analysis or when replacing the 0732611049: FILTER INSERT.
- Difficulty engaging or disengaging gears: A misaligned key prevents the shaft from seating correctly, leading to rough shifting or complete inability to select certain gears.
Technical Specifications
| Parameter | Value |
|---|---|
| Part Number | 0631.501.213 |
| Product Type | Fitted Key (Parallel Key) |
| Material | Case-hardened alloy steel (DIN 6885) |
| Width (mm) | 12.0 |
| Height (mm) | 8.0 |
| Length (mm) | 45.0 |
| Weight (g) | 34 |
| OEM Reference | ZF 0631.501.213 |
| Hardness | HRC 50-55 |
Compatibility
This fitted key is primarily designed for the ZF WG 65 Series transmission. Based on its dimensional profile and keyway geometry, it is also compatible with the following ZF models: WG180, WG200, WG210, and WG250 series. Always verify the keyway dimensions in your specific transmission housing before installation. The 0631.501.213 key works in conjunction with the 0636011038: HEXAGON SCREW, 0636011118: HEXAGON SCREW, and 0636016015: HEXAGON SCREW to secure the entire shaft assembly within the housing.
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 |
| 0634313118 | O-RING | Seal between housing sections |
| 0636304019 | SCREW PLUG | Oil drain port closure |
| 0634801152 | SEALING RING | Gasket for plug interface |
| 0732611049 | FILTER INSERT | Oil filtration element |
| 0634303718 | O-RING | Seal for filter housing |
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