Overview
The ZF 4644.183.098 is a critical OEM genuine component engineered specifically for the WG 158 series transmission. This precision-machined part functions as a key interface within the hydraulic control circuit, regulating fluid flow to ensure smooth gear engagement and consistent torque delivery. The SKU 4644.183.098 sits adjacent to the main valve body assembly, where it modulates pressure for clutch pack actuation. As a direct replacement for worn units, this part restores the transmission’s ability to maintain proper line pressure, directly impacting shift quality and overall driveline efficiency. It is designed to integrate seamlessly with the TRANSMISSION HOUSING and the SHIFT SYSTEM to form a reliable hydraulic seal.
Symptoms of Failure
When the 4644.183.098 begins to degrade, operators will notice distinct performance issues. Oil leaks around the valve body area are the most common early indicator, often appearing as drips near the transmission pan gasket. Erratic gear engagement or delayed shifting occurs as internal wear disrupts hydraulic pressure regulation, causing the transmission to hesitate before moving into drive or reverse. A third symptom is intermittent gear slipping under load, particularly when climbing grades or towing heavy equipment, as the component fails to maintain consistent clamping force on the clutch packs. Finally, contaminated transmission fluid with metallic particles may appear during routine service, signaling that the part’s internal surfaces are wearing against the GEAR SHIFT HOUSING.
Technical Specifications
| Specification | Detail |
|---|---|
| OEM Part Number | 4644.183.098 |
| Material | Hardened alloy steel with corrosion-resistant coating |
| Weight | 0.85 kg (1.87 lbs) |
| Length | 142 mm |
| Width | 38 mm |
| Height | 28 mm |
| OEM Reference | ZF WG 158 Series |
| Operating Pressure | 12–18 bar (174–261 psi) |
| Temperature Range | -40°C to +120°C |
Compatibility
This genuine ZF part is primarily designed for the WG 158 transmission series, but it also fits select models in the WG 180 and WG 200 families due to shared hydraulic architecture. It is compatible with ZF WG158, WG180, and WG200 transmissions manufactured after 2008. The part directly interfaces with the SCREW-IN SLEEVE that secures the valve body assembly. For applications in heavy-duty trucks, construction loaders, and agricultural tractors, verify your transmission’s serial number against ZF’s compatibility matrix before installation.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4644101190 | TRANSMISSION HOUSING | Encloses and supports all internal transmission components |
| 4644159347 | SHIFT SYSTEM | Controls gear selection and hydraulic valve actuation |
| 4475280036 | SCREW-IN SLEEVE | Provides threaded mounting point for valve body retention |
| 4644306511 | GEAR SHIFT HOUSING | Houses shift forks and selector mechanisms |
| 4644306440 | PISTON | Converts hydraulic pressure into mechanical force for clutch engagement |
| 0635470104 | ROLLER | Reduces friction in shift rail movement |
| 0730006344 | RING | Seals hydraulic passages between valve body sections |
| 0730006345 | RING | Provides secondary sealing for high-pressure circuits |
| 0730006346 | RING | Prevents cross-leakage between clutch feed ports |
| 0730006347 | RING | Maintains pressure integrity in the shift valve bore |
Frequently Asked Questions
Q: How do I know if the 4644.183.098 is the correct part for my WG158 transmission?
A: Check the stamped serial number on your transmission’s data plate. If it begins with “WG158” and the transmission was built after 2008, this part is compatible. Always cross-reference with the TRANSMISSION HOUSING part number to confirm the assembly revision.
Q: Can I replace this part without removing the entire transmission?
A: Yes, in most cases the 4644.183.098 is accessible after draining the fluid and removing the transmission oil pan. However, you will need to detach the SHIFT SYSTEM linkage to access the valve body. Professional installation is recommended to avoid damaging the SCREW-IN SLEEVE during reassembly.
Q: What other seals should I replace when installing this part?
A: It is strongly advised to replace all sealing rings in the valve body area simultaneously. The RING (0730006344) and RING (0730006345) are common wear items that should be renewed to prevent future leaks.
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Phone: +86 158 2286 3467 |
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