Overview
The ZF 0731.611.079 ORIFICE is a precision-machined hydraulic flow restrictor designed specifically for the WG 94 series transmission. This OEM genuine part regulates oil pressure and flow within the valve body assembly, ensuring precise clutch and brake application timing. The SKU 0731.611.079 is a critical component for maintaining shift quality and preventing hydraulic surge in heavy-duty ZF off-highway transmissions. It sits directly in the main control bore, often adjacent to the 4143101022 HOUSING and the 4143301044 HOUSING, where it meters oil to downstream circuits.
Symptoms of Failure
- Erratic or delayed gear engagement: A worn or clogged orifice disrupts hydraulic timing, causing hesitation when shifting from neutral to drive or reverse.
- Transmission oil leaks at the valve body: If the orifice housing cracks or the sealing surface degrades, pressurized oil can escape, leading to visible drips near the control module.
- Harsh or slipping shifts under load: Incorrect oil flow through the 0731.611.079 orifice results in either abrupt clutch application or insufficient holding pressure during torque converter lockup.
- Increased operating temperature: Restricted flow forces the transmission to work harder, generating excess heat that may trigger warning codes on the dash.
Technical Specifications
| Parameter | Value |
|---|---|
| Part Number | 0731.611.079 |
| OEM Reference | ZF 0731.611.079 |
| Material | Hardened steel with zinc-nickel plating |
| Orifice Diameter | 1.2 mm (0.047 in) |
| Overall Length | 18.5 mm |
| Thread Size | M10 x 1.0 |
| Weight | 8 grams |
| Sealing Method | O-ring groove (O-ring not included) |
Compatibility
This ZF 0731.611.079 orifice is engineered for the WG 94 transmission series, which includes models such as the WG94, WG180, WG200, and WG240. It is also used in certain variants of the WG 92 and WG 98 series where identical hydraulic control blocks are employed. Always verify your transmission model tag before installation. The orifice works in conjunction with the 0631329135 SPRING PIN and 0636302014 SCREW PLUG to secure the valve body assembly.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4143101022 | HOUSING | Main valve body housing for oil distribution |
| 4143301044 | HOUSING | Secondary housing for clutch control circuits |
| 0631329135 | SPRING PIN | Retains orifice and prevents rotation |
| 0636302014 | SCREW PLUG | Seals the orifice bore access port |
| 0634801057 | SEALING RING | Provides leak-proof seal at plug interface |
| 4143301053 | CONNECTING PART | Links valve body sections for oil flow |
| 0636100600 | CAP SCREW | M6 fastener for housing attachment |
| 0636101024 | CAP SCREW | M8 fastener for high-torque applications |
| 0730365159 | TYPE PLATE | Identification plate for transmission model |
| 0631311009 | GROOVED STUD | Alignment dowel for precise housing positioning |
