Overview
The ZF 0731.590.188 THREADED BUSH is a precision-engineered component designed specifically for the WG 250 Series transmission. This OEM genuine part serves as a critical interface point, providing a durable threaded mounting surface within the transmission housing assembly. Its primary function is to secure adjacent components and maintain precise alignment under high-torque conditions. The SKU 0731.590.188 is manufactured to ZF’s exacting tolerances, ensuring a perfect fit and long service life. This threaded bush is typically located near the main housing interface, where it works in conjunction with the TRANSMISSION HOUSING to anchor internal assemblies.
Symptoms of Failure
When the ZF 0731.590.188 threaded bush wears out, operators may notice specific performance issues. Look for these common failure symptoms:
- Oil seepage around the housing joint: A worn bush can compromise the seal between the HOUSING and the COVER, leading to visible fluid leaks.
- Loose mounting points: If the threads strip or deform, fasteners like the HEXAGON SCREW may not tighten properly, causing vibration or rattling.
- Abnormal gear engagement noise: Misalignment from a failing bush can create a whining or grinding sound during shifting.
- Reduced clamping force: Over time, the bush may crack or distort, leading to inconsistent pressure on the transmission housing assembly.
Technical Specifications
| Specification | Detail |
|---|---|
| Part Number | 0731.590.188 |
| Material | Case-hardened steel (C45E) |
| Thread Size | M12 x 1.5 (internal) |
| Outer Diameter | 22.0 mm |
| Length | 28.5 mm |
| Weight | 0.045 kg |
| OEM Reference | ZF 0731.590.188 |
| Surface Treatment | Zinc-plated (DIN 50979) |
Compatibility
This threaded bush is engineered for the ZF WG 250 Series, but it also fits several other ZF transmission models that share the same housing architecture. Compatible transmissions include:
- ZF WG 250
- ZF WG 180
- ZF WG 200
- ZF WG 150
- ZF WG 300 (early production)
Always verify the thread pitch and housing bore dimensions before installation. The bush interfaces directly with the TRANSMISSION HOUSING and the HOUSING assembly.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4646101066 | TRANSMISSION HOUSING | Main structural casing for gear sets |
| 4646301228 | HOUSING | Secondary housing component for clutch packs |
| 4646301251 | COVER | Seals the housing assembly |
| 0636015304 | HEXAGON SCREW | Fastens the bush to the housing |
| 0636101828 | CAP SCREW | Secures cover plates |
| 4646301100 | COVER SHEET | Thin protective plate |
| 4646301217 | COVER SHEET | Alternate cover sheet variant |
| 4646201007 | SCREEN SHEET | Filter screen for oil flow |
| 0730365125 | TYPE PLATE | Identification tag for transmission |
| 0631311009 | GROOVED STUD | Alignment pin for housing assembly |
