Overview
The ZF 4642.351.078 Thrust Plate is a precision-engineered component designed to manage axial loads and maintain critical clearances within the WG150 and WG180 series transmissions. Positioned between the planetary gear set and the transmission housing, this OEM genuine part absorbs end-play forces that would otherwise cause gear misalignment and premature wear. The SKU 4642.351.078 is manufactured to ZF’s exacting tolerances, ensuring consistent oil film distribution and stable shaft positioning under high-torque conditions. When paired with a properly sealed TRANSMISSION HOUSING or a reinforced TRANSMISSION HOUSING, this thrust plate forms the backbone of the transmission’s load-bearing architecture.
Symptoms of Failure
- Gradual gear slipping under load: As the thrust plate wears, axial clearance increases, causing the clutch packs to lose engagement pressure. This often manifests as a “soft” shift or delayed acceleration in WG150-equipped vehicles.
- Metallic grinding noise from the bell housing: A worn 4642.351.078 allows the planetary carrier to contact the housing, producing a distinct low-frequency grinding sound during deceleration or when shifting into reverse.
- Oil contamination with bronze particles: The thrust plate’s bearing surface sheds fine metallic debris into the transmission fluid. Inspecting the oil pan often reveals a bronze-colored sludge, indicating the plate has exceeded its service life.
- Erratic hydraulic pressure readings: Excessive axial movement caused by a degraded thrust plate disrupts oil flow to the valve body, leading to pressure fluctuations that trigger fault codes in electronic control units.
Technical Specifications
| Parameter | Value |
|---|---|
| Part Number | 4642.351.078 |
| Material | Hardened steel with bronze overlay |
| Outer Diameter | 142 mm |
| Inner Diameter | 68 mm |
| Thickness | 4.2 mm |
| Weight | 0.34 kg |
| OEM Reference | ZF 4642.351.078 |
| Surface Finish | Ground, Ra ≤ 0.8 µm |
Compatibility
This thrust plate is a direct fit for the ZF WG150 and WG181 transmission families. It also serves as a service replacement for the WG180 series when axial clearance specifications match. The part is commonly used in WG200 variants that share the same planetary carrier geometry. Always verify the transmission serial number against the OEM parts catalog, as some early WG151 models may require a different thrust washer configuration. For proper installation, ensure the TYPE PLATE is legible to confirm the exact transmission model, and use a GROOVED STUD to secure the assembly during reassembly.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4642101108 | TRANSMISSION HOUSING | Encloses the gear train and supports the thrust plate |
| 4642301208 | TRANSMISSION HOUSING | Alternate housing variant for WG181 series |
| 0730365125 | TYPE PLATE | Identifies transmission model and revision |
| 0631311009 | GROOVED STUD | Locates and aligns the thrust plate during assembly |
| 4642301168 | SCREEN SHEET | Filters debris from the lubrication circuit |
| 4642301169 | SCREEN SHEET | Fine-mesh variant for high-contamination environments |
| 0636100621 | HEXAGON SCREW | Secures the housing to the transmission case |
| 0630361029 | SEALING CAP | Prevents oil leakage from the housing bore |
| 4642306254 | ADAPTER | Converts housing port for alternate cooler lines |
| 0634303340 | O-RING | Seals the thrust plate bore against pressure loss |
