Overview
The ZF 4657.183.373 LOOSE PARTS for WG191 is a critical service kit designed to restore the precise internal clearances within the WG 191 Series transmission. This genuine OEM part, identified by SKU 4657.183.373, contains the specific shims, seals, and adjustment components that sit between the main housing sections. When installed alongside the TRANSMISSION HOUSING (4657101049) and the HOUS.FRONT SECT (4657301130), this kit ensures the planetary gear sets maintain correct axial play, preventing internal contact and premature wear. It is an indispensable element for any full overhaul of the WG191 gearbox.
Symptoms of Failure
- Intermittent gear slippage under load: When the loose parts (shims and thrust washers) wear, the clutch packs lose their clamping force, causing the transmission to slip during heavy acceleration or hill climbing.
- Low hydraulic pressure warnings: Deteriorated sealing elements within this kit can cause internal fluid bypass, leading to a drop in line pressure and erratic shift timing.
- Metallic debris in the oil pan: As the clearance between the HOUSING REAR PART (4657301131) and the rotating assembly increases, metal particles shed from the gears and bearings, contaminating the transmission fluid.
- Audible whining or grinding from the bell housing: Excessive axial movement due to worn adjustment components creates a distinct high-pitched noise that changes with engine RPM.
Technical Specifications
| Parameter | Specification |
|---|---|
| Part Number (SKU) | 4657.183.373 |
| Material Composition | Hardened steel shims with nitrile rubber seals |
| Weight | 0.45 kg (1.0 lb) |
| Dimensions (L x W x H) | 120 mm x 80 mm x 15 mm |
| OEM Reference | ZF 4657.183.373 |
| Application | WG 191 Series |
Compatibility
This genuine ZF part is engineered specifically for the WG 191 transmission series. While the kit is dimensionally unique to the WG191, its adjustment principles apply to the broader WG family, including the WG180 and WG200 models. However, for guaranteed fitment, we recommend verifying the housing casting numbers against the CYLINDRICAL PIN (0631306816) alignment points. The 4657.183.373 kit is not interchangeable with older WG150 or WG250 variants due to differences in the front section bore diameter.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4657101049 | TRANSMISSION HOUSING | Main structural casing for gear train |
| 4657301130 | HOUS.FRONT SECT | Front section housing for pump and converter |
| 4657301131 | HOUSING REAR PART | Rear section supporting output shaft |
| 0631306816 | CYLINDRICAL PIN | Alignment dowel for housing assembly |
| 0636102489 | CAP SCREW | Fastener for front housing attachment |
| 4656301148 | FIXING PLATE | Retains valve body in position |
| 0636102463 | CAP SCREW | Bolt for rear housing flange |
| 4657201133 | SCREEN SHEET | Oil filter mesh for hydraulic circuit |
| 0636115287 | CAP SCREW | Fastener for oil pan |
| 4657301065 | PLATE | Spacer plate between housing sections |
