Overview
The ZF 0737.835.154 UNION SCREW is a critical hydraulic sealing and connection component engineered specifically for the WG 200 and WG 210 series transmissions. This OEM genuine part functions as a high-pressure port fitting, securing fluid passages within the valve body and clutch housing assembly. It ensures a leak-free interface between the transmission housing and hydraulic circuits, maintaining precise oil pressure for smooth gear engagement. The SKU 0737.835.154 is a direct replacement for the original factory component, guaranteeing exact thread pitch and sealing geometry.
Symptoms of Failure
When the 0737.835.154 UNION SCREW degrades or loosens, operators often report transmission fluid weeping from the union screw port, particularly during cold starts. Another common failure mode is intermittent gear slippage under load, caused by pressure loss at the screw interface. Technicians also note erratic shift timing as the hydraulic control unit receives inconsistent fluid volume. In severe cases, external oil spray on the bell housing indicates a complete seal failure requiring immediate replacement.
Technical Specifications
| Parameter | Specification |
|---|---|
| Part Number | 0737.835.154 |
| Material | Case-hardened steel with zinc-nickel plating |
| Thread Size | M18 x 1.5 (estimated) |
| Overall Length | 32 mm |
| Hex Head Size | 22 mm |
| Weight | 0.045 kg |
| OEM Reference | ZF 0737.835.154 |
| Sealing Method | Integrated O-ring groove (O-ring sold separately) |
Compatibility
This UNION SCREW is validated for use in the following ZF transmission platforms: WG180, WG200, WG210, and select variants of the WG190 series. It is commonly installed on the main pressure gallery of the 4644101216: TRANSMISSION HOUSING and the 4644301223: TRANSMISSION HOUSING. Always verify thread compatibility with your specific housing casting number before installation.
During rebuild procedures, this screw is torqued adjacent to the 0730365067: TYPE PLATE which identifies the transmission model. The assembly also requires the 0631311009: GROOVED STUD for proper alignment of the valve body cover.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4644101216 | TRANSMISSION HOUSING | Main structural casing for gear train |
| 4644301223 | TRANSMISSION HOUSING | Rear housing section for WG200/210 |
| 0730365067 | TYPE PLATE | Model identification tag |
| 0631311009 | GROOVED STUD | Alignment dowel for cover plates |
| 4644303060 | COVER PLATE | Access cover for valve body |
| 4644303061 | COVER PLATE | Alternate cover plate variant |
| 0634306525 | O-RING | Seal for union screw port |
| 0636305026 | SCREW PLUG | Hydraulic test port plug |
| 4644301279 | SCREEN SHEET | Filter mesh for oil pickup |
| 4644301088 | SEALING CAP | Dust cap for unused ports |
