Overview
The ZF 0630.361.052 SEALING CAP is a critical OEM genuine component engineered for the WG 65 Series transmission family. This precision-molded cap seals the hydraulic control unit or valve body bore, preventing pressurized transmission fluid from escaping and blocking external contaminants from entering the system. Installed directly into the transmission housing, the 0630.361.052 ensures consistent internal pressure essential for smooth gear engagement. When replacing this cap, always inspect the adjacent TRANSMISSION HOUSING for cracks or wear, as a compromised housing can accelerate seal failure.
Symptoms of Failure
- External transmission fluid seepage around the valve body area: A worn or brittle 0630.361.052 cap loses its interference fit, allowing ATF to weep past the sealing lip, often visible as dark residue on the housing exterior.
- Erratic or delayed gear engagement: When the sealing cap fails, hydraulic pressure drops inside the control circuit, causing sluggish shifts or momentary loss of drive in forward or reverse gears.
- Contaminated transmission fluid with metallic particles: A cracked cap permits debris from the housing cavity to enter the oil gallery, accelerating wear on clutches and bearings.
- Whining or buzzing noise from the transmission pump: Air ingestion through a degraded seal creates cavitation, producing a high-pitched sound that worsens under load.
Technical Specifications
| Part Number | 0630.361.052 |
| Product Name | SEALING CAP |
| Material | Nitrile rubber (NBR) with steel insert |
| Outer Diameter | 28.5 mm |
| Inner Diameter | 18.0 mm |
| Height | 12.0 mm |
| Weight | 0.015 kg |
| OEM Reference | ZF 0630.361.052 |
| Hardness (Shore A) | 70 ± 5 |
| Temperature Range | -40°C to +150°C |
Compatibility
This sealing cap is specifically designed for the ZF WG 65 Series transmissions, including models WG65, WG80, WG100, WG120, WG150, WG180, and WG200. It is also used in select off-highway and industrial driveline variants that share the same valve body architecture. Always verify fitment by cross-referencing your transmission serial number. For secure installation, pair this cap with the correct HEXAGON SCREW (M8 x 20) and the HEXAGON SCREW (M10 x 25) for the housing flange. Use the HEXAGON SCREW (M12 x 30) for high-torque applications on the main case.
Related Components
| Part Number | Name | Function |
|---|---|---|
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| 0636016015 | HEXAGON SCREW | M12 fastener for main case |
| 0631306085 | CYLINDRICAL PIN | Alignment dowel for housing positioning |
| 0634313118 | O-RING | Static seal for valve body cover |
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| 0732611049 | FILTER INSERT | Hydraulic oil filtration element |
| 0634303718 | O-RING | Internal seal for pressure line connection |
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