Overview
The ZF 4644.120.007 PRESSURE REGULATOR is a precision-engineered hydraulic control component designed for the WG150, WG180, and WG200 series transmissions. This OEM genuine part modulates fluid pressure within the valve body assembly, ensuring consistent clutch engagement and smooth gear shifts under heavy load conditions. The SKU 4644.120.007 directly replaces worn factory units to restore original shift quality. When installed alongside a robust TRANSMISSION HOUSING (4642101108) or the TRANSMISSION HOUSING (4642301208), this regulator maintains the precise hydraulic balance required for long service intervals in industrial drivetrains.
Symptoms of Failure
- Erratic or delayed gear engagement: A failing pressure regulator causes inconsistent hydraulic force, leading to harsh or delayed shifts when accelerating from a stop.
- Transmission oil leaks around the valve body: Worn internal seals allow pressurized fluid to escape, often visible as drips near the regulator mounting point.
- Gear slipping under load: Insufficient pressure regulation results in clutch pack slippage during uphill climbs or towing, accompanied by rising transmission temperatures.
- Fluctuating line pressure readings: Diagnostic tests reveal unstable pressure values that cannot be corrected without replacing the regulator unit.
Technical Specifications
| Parameter | Specification |
|---|---|
| Part Number / SKU | 4644.120.007 |
| OEM Reference | ZF 4644.120.007 |
| Material | Hardened steel with corrosion-resistant coating |
| Weight | 0.85 kg (1.87 lbs) |
| Dimensions (L x W x H) | 95 mm x 45 mm x 40 mm |
| Operating Pressure Range | 8–22 bar (116–319 psi) |
| Seal Type | Integrated O-ring (compatible with O-RING 0634303340) |
Compatibility
This pressure regulator is engineered for ZF WG150, WG180, and WG200 series transmissions used in construction, agricultural, and material handling equipment. It directly fits valve bodies in the WG150 and WG180 models, and is also backward-compatible with select WG200 variants when paired with the correct ADAPTER (4642306254). Always verify the TYPE PLATE (0730365125) on your transmission housing to confirm model designation before installation. The regulator mounts securely using a GROOVED STUD (0631311009) to prevent vibration loosening.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4642101108 | TRANSMISSION HOUSING | Main structural casing for gear and valve assemblies |
| 4642301208 | TRANSMISSION HOUSING | Alternative housing variant for WG180 series |
| 0730365125 | TYPE PLATE | Identification plate with transmission model and serial number |
| 0631311009 | GROOVED STUD | Threaded fastener for securing pressure regulator |
| 4642301168 | SCREEN SHEET | Fine mesh filter for hydraulic fluid intake |
| 4642301169 | SCREEN SHEET | Secondary filter screen for high-flow circuits |
| 0636100621 | HEXAGON SCREW | M8 hex bolt for housing and valve body fastening |
| 0630361029 | SEALING CAP | Protective cap for unused hydraulic ports |
| 4642306254 | ADAPTER | Mounting adapter for regulator compatibility across series |
| 0634303340 | O-RING | Elastomeric seal for pressure regulator base |
