Overview
The ZF 4644.183.020 LOOSE PARTS kit is a critical service component designed specifically for the WG 201 series transmission. This genuine OEM assembly contains the essential fasteners, seals, and positioning elements required to secure internal hydraulic circuits and maintain structural integrity within the gearbox. As a loose parts set, it replaces worn or missing hardware that can compromise the alignment of the TRANSMISSION HOUSING and the TRANSMISSION HOUSING assembly. The SKU 4644.183.020 is factory-sourced to ensure exact fitment and material hardness, preventing premature loosening under high-torque conditions.
Symptoms of Failure
- Oil weeping from housing joints: When the loose parts degrade, the seal between the THREADED BUSH and the housing fails, leading to visible fluid seepage around the bell housing.
- Intermittent gear slippage under load: Worn fasteners allow the valve body to shift minutely, causing delayed engagement or clutch pack chatter during acceleration.
- Abnormal metallic rattling at idle: Loose internal components vibrate against the SCREW PLUG and adjacent bores, producing a distinct noise that intensifies with transmission temperature.
- Erratic shift timing: Degraded hardware alters hydraulic pressure paths, resulting in harsh or delayed shifts between 2nd and 3rd gear.
Technical Specifications
| Parameter | Specification |
|---|---|
| Part Number | 4644.183.020 |
| OEM Reference | ZF 4644.183.020 |
| Material | Case-hardened steel with zinc-nickel plating |
| Weight | 0.42 kg (0.93 lbs) |
| Dimensions | 120 mm x 80 mm x 30 mm (kit envelope) |
| Compatible Series | WG 201 |
| Thread Pitch | M8 x 1.25 (primary fasteners) |
Compatibility
This genuine ZF 4644.183.020 LOOSE PARTS kit is engineered for the WG 201 transmission family. It is also suitable for select WG 180 and WG 200 variants that share the same housing bolt pattern and hydraulic circuit layout. The kit integrates directly with the TRANSMISSION HOUSING and the TRANSMISSION HOUSING to restore factory clamping force. Always verify your transmission model suffix against the ZF parts catalog before installation.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4644101160 | TRANSMISSION HOUSING | Main structural casing for gear train |
| 4644301323 | TRANSMISSION HOUSING | Secondary housing for valve body support |
| 4644301189 | THREADED BUSH | Wear-resistant insert for fastener alignment |
| 4475280043 | SCREW PLUG | Seals hydraulic test ports |
| 0634306198 | O-RING | Prevents fluid bypass at joint interfaces |
| 0730365067 | TYPE PLATE | Identification tag for transmission model |
| 4644301161 | COVER PLATE | Protects internal components from debris |
| 0636100621 | HEXAGON SCREW | Secures housing halves together |
| 0631610020 | SET SCREW | Locks adjustment mechanisms in place |
| 0501218540 | BREATHER | Equalizes internal pressure and vents moisture |
