Overview
The ZF 4644.183.023 LOOSE PARTS for WG200 is a critical internal component designed to maintain precise hydraulic control within the WG 200 Series transmission. This OEM genuine part functions as a valve body or actuation sub-assembly, regulating oil flow to clutch packs and shift elements. As a loose parts kit, it includes the necessary hardware for direct replacement without requiring a full valve body overhaul. The SKU 4644.183.023 is engineered to ZF’s exact tolerances, ensuring consistent shift quality and preventing pressure loss in the transmission’s hydraulic circuit. This part sits directly within the main control unit, interfacing with the 4644101249: TRANSMISSION HOUSING and the 4644301402: TRANSMISSION HOUSING to form a sealed hydraulic system.
Symptoms of Failure
When the ZF 4644.183.023 LOOSE PARTS begins to wear, operators will notice distinct performance degradation. Common failure symptoms include:
- Erratic shift timing or gear slipping – Worn internal components cause inconsistent clutch application, leading to delayed or harsh shifts under load.
- Hydraulic fluid leaks around the valve body area – Degraded seals or cracked bores in the 4644.183.023 assembly allow pressurized oil to escape, reducing line pressure.
- Transmission overheating – Inefficient oil routing from a failing loose parts kit forces the system to work harder, generating excess heat.
- No reverse engagement or delayed forward drive – Specific valve wear can block oil flow to certain clutch packs, causing intermittent drive loss.
Technical Specifications
| Parameter | Value |
|---|---|
| Part Number | 4644.183.023 |
| Type | Loose Parts Kit (Valve Body Sub-Assembly) |
| Material | Hardened Steel / Aluminum Alloy |
| Weight | 0.85 kg (1.87 lbs) |
| OEM Reference | ZF 4644.183.023 |
| Compatible Housing | 4644101249 / 4644301402 |
| Sealing Component | 0634306323: O-RING |
| Cover Plate | 4644301298: COVER PLATE |
Compatibility
This OEM genuine part is primarily designed for the ZF WG 200 Series transmissions, including the WG180, WG200, and WG210 variants. It is also compatible with select off-highway and industrial ZF models that share the same valve body architecture, such as the 4WG200 and 5WG200. Always verify the housing interface; the 4644.183.023 integrates directly with the 4644301298: COVER PLATE and requires the 0634306323: O-RING for proper sealing. For complete rebuilds, pair this part with the 4644298503: REPAIR KIT to ensure all wear items are replaced simultaneously.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4644101249 | TRANSMISSION HOUSING | Main structural casing for valve body assembly |
| 4644301402 | TRANSMISSION HOUSING | Alternate housing variant for WG200 |
| 4644301298 | COVER PLATE | Seals and protects valve body components |
| 0634306323 | O-RING | Hydraulic seal between housing and cover |
| 0636305026 | SCREW PLUG | Closes oil passages during service |
| 4644301279 | SCREEN SHEET | Filters debris from hydraulic fluid |
| 4644301088 | SEALING CAP | Prevents contamination of open ports |
| 4644298503 | REPAIR KIT | Complete gasket and seal set for overhaul |
| 4644309001 | OUTPUT FLANGE | Transfers torque from transmission to driveline |
| 4475280079 | SCREW PLUG | High-pressure port sealing plug |
