Overview
The ZF 6073.015.205 EST 37 A for WG191 is a critical electro-hydraulic solenoid valve assembly that modulates clutch pressure within the transmission control unit. This OEM genuine part, identified by SKU 6073.015.205, sits directly on the valve body of the WG 191 Series, translating electronic shift commands into precise hydraulic actuation. When functioning correctly, it ensures seamless gear engagement and consistent torque delivery. This component works in concert with the 4657101049: TRANSMISSION HOUSING to maintain structural integrity and fluid routing within the assembly.
Symptoms of Failure
- Erratic shifting or gear hunting: A failing EST 37 A causes the transmission to slip between gears or hunt for the correct ratio, especially under load.
- Delayed engagement from Neutral to Drive: Operators notice a 2-3 second lag when shifting from park or neutral into a forward gear.
- Intermittent loss of forward or reverse: The solenoid may fail to hold pressure, resulting in sudden loss of drive in one direction.
- Transmission overheating due to clutch slippage: Incomplete clutch pack engagement generates excess heat, often flagged by the temperature warning system.
Technical Specifications
| Parameter | Specification |
|---|---|
| Part Number | 6073.015.205 |
| OEM Reference | ZF EST 37 A |
| Material | Hardened steel spool with aluminum housing |
| Weight | 0.85 kg (1.87 lbs) |
| Operating Pressure | 8–22 bar |
| Coil Resistance | 5.4 Ω ± 0.3 Ω at 20°C |
| Seal Type | NBR O-rings (included) |
Compatibility
This solenoid is engineered for the ZF WG 191 Series but also fits select variants of the WG180 and WG200 transmissions. It is a direct replacement for units using the EST 37 A valve block configuration. The part interfaces with the 4657301130: HOUS.FRONT SECT and the 4657301131: HOUSING REAR PART, which enclose the valve body assembly. A 0631306816: CYLINDRICAL PIN is used to align the solenoid during installation.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4657101049 | TRANSMISSION HOUSING | Main structural casing for gear train |
| 4657301130 | HOUS.FRONT SECT | Front section of valve body housing |
| 4657301131 | HOUSING REAR PART | Rear section enclosing solenoid pack |
| 0631306816 | CYLINDRICAL PIN | Alignment dowel for solenoid mounting |
| 0636102489 | CAP SCREW | M8 fastener for housing assembly |
| 4656301148 | FIXING PLATE | Retains solenoid in valve body |
| 0636102463 | CAP SCREW | M6 bolt for valve body attachment |
| 4657201133 | SCREEN SHEET | Filter mesh for hydraulic fluid |
| 0636115287 | CAP SCREW | M10 bolt for rear housing |
| 4657301065 | PLATE | Spacer plate between valve sections |
