Overview
The ZF 4644.199.297 LOOSE PARTS kit is a critical service assembly designed specifically for the WG 201 series transmission. This OEM genuine part set contains the necessary loose components required to restore proper sealing and mechanical integrity within the valve body and hydraulic control unit. The SKU 4644.199.297 is frequently ordered during a major overhaul to replace worn fasteners, bushings, and sealing elements that degrade over time. When installed alongside a new TRANSMISSION HOUSING (4644101203) or a TRANSMISSION HOUSING (4644301382), this kit ensures the internal pressure circuits remain leak-free and the shift quality is restored to factory specifications.
Symptoms of Failure
When the components within the 4644.199.297 LOOSE PARTS kit begin to fail, operators will notice distinct performance degradation. Common failure symptoms include:
- Hydraulic fluid seepage around the valve body mating surfaces – Worn sealing rings and bushings allow ATF to bypass, leading to low line pressure and erratic shifting.
- Delayed engagement or gear slippage under load – A failing THREADED BUSH (4644301189) can cause incorrect valve alignment, resulting in clutch pack slip during acceleration.
- Intermittent neutral conditions or harsh upshifts – Loose or fatigued fasteners such as the SCREW PLUG (0636302005) can create pressure spikes that confuse the shift logic.
- Visible metal debris in the transmission pan – Worn loose parts shed microscopic particles that accelerate wear on adjacent components like the O-RING (0634306198).
Technical Specifications
| Specification | Value |
|---|---|
| Part Number / SKU | 4644.199.297 |
| Material Composition | Steel, brass, nitrile rubber (NBR) |
| Weight (approx.) | 0.45 kg (1.0 lb) |
| OEM Reference | ZF 4644.199.297 |
| Thread Pitch (primary) | M10 x 1.5 |
| Operating Temperature Range | -40°C to +120°C |
| Hardness (bushings) | HRC 28-32 |
Compatibility
This LOOSE PARTS kit is engineered for the ZF WG 201 series transmission family. It is directly compatible with the WG180, WG200, and WG210 models that share the same valve body architecture. The kit also applies to certain WG 211 variants produced after 2015. For proper fitment, always verify the transmission serial number and consult the parts manual. When replacing these loose parts, it is strongly recommended to also inspect the SEALING RING (0634801098) and the TYPE PLATE (0730365067) for wear.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4644101203 | TRANSMISSION HOUSING | Main structural casing for gear train |
| 4644301382 | TRANSMISSION HOUSING | Alternate housing variant for WG201 |
| 4644301189 | THREADED BUSH | Provides wear-resistant thread for valve body |
| 0636302005 | SCREW PLUG | Seals hydraulic passages |
| 0634306198 | O-RING | Static seal for housing joints |
| 0634801098 | SEALING RING | Dynamic seal for rotating shafts |
| 0730365067 | TYPE PLATE | Identification plate for transmission |
| 0631311009 | GROOVED STUD | Alignment pin for valve body |
| 4644301161 | COVER PLATE | Protects internal components |
| 0636100621 | HEXAGON SCREW | Fastener for housing assembly |
