Overview
The ZF 0631.306.126 CYLINDRICAL PIN is a precision-engineered locating component designed specifically for the WG 65 series heavy-duty transmission. This OEM genuine part serves as a critical alignment dowel within the transmission housing assembly, ensuring exact positioning of mating components during gear train operation. The SKU 0631.306.126 is manufactured to ZF’s stringent tolerances to prevent axial movement and maintain concentricity under high-torque loads. It is installed directly into the TRANSMISSION HOUSING to secure internal assemblies against vibration and thermal expansion.
Symptoms of Failure
- Transmission housing misalignment causing oil leaks: A worn or sheared cylindrical pin allows the housing halves to shift, leading to pressurized fluid escaping past gaskets. This often manifests as drips near the bell housing or output flange.
- Gear engagement noise during shifting: When the pin loses its interference fit, gear shafts can drift out of parallel, producing a distinct grinding or whining sound when selecting forward or reverse gears.
- Premature bearing wear: Without proper pin retention, bearings experience uneven loading, resulting in metallic debris in the oil pan and reduced transmission service life.
- Hexagon screw loosening: A failing pin allows the HEXAGON SCREW and HEXAGON SCREW fasteners to back out under vibration, requiring frequent retorquing.
Technical Specifications
| Parameter | Value |
|---|---|
| Part Number | 0631.306.126 |
| Type | Cylindrical Pin (Dowel Pin) |
| Material | Case-hardened alloy steel (DIN 6325 equivalent) |
| Diameter | 12 mm (nominal) |
| Length | 30 mm |
| Surface Hardness | 58-62 HRC |
| Weight | Approx. 27 grams |
| OEM Reference | ZF 0631.306.126 |
| Installation Torque | N/A (press-fit component) |
Compatibility
This cylindrical pin is a direct fit for the ZF WG 65 series transmission family, including models such as WG65, WG80, WG120, WG150, WG180, and WG200. It is also used in certain off-highway variants of the Ecomat and Ecolife series where identical housing alignment is required. Always verify the part number 0631.306.126 against your transmission’s serial plate before installation. For proper assembly, pair this pin with the HEXAGON SCREW to secure the housing cover.
Related Components
| Part Number | Name | Function |
|---|---|---|
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| 0636016015 | HEXAGON SCREW | Fastener for oil pan |
| 0631306085 | CYLINDRICAL PIN | Alternative alignment pin for smaller housings |
| 0634313118 | O-RING | Seals hydraulic passages |
| 0636304019 | SCREW PLUG | Closes oil drain port |
| 0634801152 | SEALING RING | Prevents fluid leakage at joints |
| 0732611049 | FILTER INSERT | Traps contaminants in oil circuit |
| 0634303718 | O-RING | Seals pressure line connection |
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