Overview
The ZF 4646.301.277 SCREEN SHEET is a critical filtration component engineered specifically for the WG 251 Series transmission. Positioned within the hydraulic control circuit, this genuine OEM part captures particulate contaminants before they can enter the valve body and clutch assemblies. By maintaining fluid cleanliness, the screen sheet ensures consistent hydraulic pressure regulation and prolongs the service life of adjacent components such as the 4646101072 TRANSMISSION HOUSING and the 4646301201 HOUSING. The SKU 4646.301.277 is precision-manufactured to ZF’s exacting tolerances, guaranteeing a perfect seal and optimal flow characteristics.
Symptoms of Failure
When the 4646.301.277 screen sheet becomes clogged or damaged, operators may notice these specific failure indicators:
- Erratic shift timing or gear slipping under load – Restricted oil flow through a blocked screen sheet starves the clutch packs, causing delayed engagement or torque loss during acceleration.
- Elevated transmission operating temperature – A contaminated screen sheet increases hydraulic resistance, forcing the pump to work harder and generating excess heat that can degrade seals and fluid.
- Whining or surging noise from the pump – Cavitation caused by insufficient fluid supply through a partially obstructed screen sheet produces audible high-pitched sounds, especially during cold starts.
- Visible metallic debris in the oil pan – A ruptured screen sheet allows wear particles to circulate, often detected during routine fluid changes as shimmering or gritty residue.
Technical Specifications
| Parameter | Specification |
|---|---|
| Part Number | 4646.301.277 |
| Material | Stainless steel mesh with reinforced polymer frame |
| Mesh Micron Rating | 125 µm (nominal) |
| Overall Dimensions | 180 mm x 120 mm x 8 mm |
| Weight | 0.14 kg |
| OEM Reference | ZF 4646.301.277 (Genuine) |
| Operating Temperature Range | -40°C to +120°C |
| Burst Pressure Rating | 25 bar |
Compatibility
This screen sheet is designed for the ZF WG 251 Series, but it also fits several other heavy-duty transmission models that share the same hydraulic sump architecture. Verified compatible transmissions include the WG180, WG200, WG211, and WG240 series. It is commonly replaced during a full overhaul alongside the 4646301166 COVER and the 0636101051 CAP SCREW to ensure a leak-free assembly. Always cross-reference your transmission’s serial number with ZF’s parts catalog before ordering.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4646101072 | TRANSMISSION HOUSING | Main structural casing for gear and clutch assembly |
| 4646301201 | HOUSING | Intermediate housing supporting valve body and oil passages |
| 4646301166 | COVER | Sealing cover for hydraulic control unit access |
| 0636101051 | CAP SCREW | Fastener securing cover and housing interfaces |
| 4646201018 | COVER SHEET | Thin gasket layer for oil channel separation |
| 4646201019 | COVER SHEET | Alternate thickness gasket for pressure regulation |
| 0730365125 | TYPE PLATE | Identification plate with transmission model and serial |
| 0631311009 | GROOVED STUD | Alignment stud for precise housing positioning |
| 0636010216 | HEXAGON SCREW | M10 bolt for high-torque housing connections |
| 0636010174 | HEXAGON SCREW | M8 bolt for low-torque cover attachments |
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