Overview
The ZF 4657.500.140 WK-VALVE is a critical hydraulic control component engineered specifically for the WG 211 transmission series. This OEM genuine part governs the modulation of clutch pressure within the torque converter lock-up (WK) circuit, ensuring smooth power transfer and preventing driveline shudder. As a precision-machined spool valve, it directly interfaces with the transmission’s valve body to regulate oil flow. The SKU 4657.500.140 is the definitive replacement identifier for this valve, guaranteeing exact fitment and factory-specified performance. When paired with a properly functioning 4657120005: PRESSURE REGULATOR, this WK-valve maintains stable system pressure across varying load conditions.
Symptoms of Failure
- Torque converter shudder or vibration during light throttle acceleration, often described as a “chuggle” at highway speeds.
- Delayed or harsh lock-up engagement when the converter attempts to couple, leading to erratic shift feel and increased transmission temperature.
- Intermittent loss of power under load, accompanied by fluctuating RPM without corresponding vehicle speed changes.
- Visible hydraulic fluid contamination in the valve body area, often caused by worn sealing edges on the spool.
Technical Specifications
| Parameter | Value |
|---|---|
| Part Number | 4657.500.140 |
| Type | WK-Valve (Torque Converter Lock-Up) |
| Material | Hardened Steel with Phosphate Coating |
| Length | 68.5 mm |
| Outer Diameter | 18.0 mm |
| Weight | 0.085 kg |
| OEM Reference | ZF 4657.500.140 |
| Operating Pressure | 8–15 bar |
Compatibility
This WK-valve is engineered for the ZF WG 211 series and its direct derivatives. It is commonly found in the following transmission models: WG180, WG200, WG211, and WG250 series. The valve is also compatible with certain off-highway variants of the WG series used in construction and agricultural equipment. For proper assembly, ensure the 0630532183: INDENTED RING is correctly seated to prevent leakage, and verify that the 4656306145: PISTON moves freely within its bore. Additionally, the 0501211384: VALVE should be inspected for scoring during replacement.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4657120005 | PRESSURE REGULATOR | Maintains stable hydraulic pressure in the valve body |
| 0501211384 | VALVE | Directs oil flow for clutch application |
| 0630532183 | INDENTED RING | Secures valve components and prevents axial movement |
| 4656306145 | PISTON | Converts hydraulic pressure into mechanical force |
| 0732042767 | COMPRESSION SPRING | Returns the valve spool to its neutral position |
| 0631612064 | SET SCREW | Adjusts valve travel limits |
| 0631610026 | SET SCREW | Locks calibration settings |
| 4657101048 | TRANSMISSION HOUSING | Encloses the entire valve body assembly |
| 4657301061 | HOUS.FRONT SECT | Front section of the transmission casing |
| 4657301062 | HOUSING REAR PART | Rear section of the transmission casing |
