Overview
This OEM genuine ZF 4644.253.050 component is a precision-engineered part designed specifically for the WG 158 series transmission. It plays a critical role in the hydraulic control circuit, regulating fluid pressure to ensure smooth clutch engagement and consistent power delivery. The SKU 4644.253.050 is a direct replacement for the original factory-installed unit, guaranteeing exact fit and performance. When installed alongside a robust TRANSMISSION HOUSING, this part helps maintain the structural integrity of the valve body assembly.
Symptoms of Failure
When the ZF 4644.253.050 begins to wear, operators often notice specific performance degradation. Look for these common failure indicators:
- Delayed or harsh shifting: Worn internal seals cause pressure loss, leading to jarring gear changes or hesitation when accelerating.
- Intermittent gear slippage: A failing unit may allow the transmission to momentarily lose power under load, especially during uphill climbs.
- Hydraulic fluid contamination: Debris from a degraded part can circulate through the system, accelerating wear on the SHIFT SYSTEM and other sensitive components.
- Visible oil seepage: Cracks or gasket failure around the mounting point often produce drips near the bell housing area.
Technical Specifications
| Part Number | 4644.253.050 |
| Material | Hardened steel alloy with corrosion-resistant coating |
| Weight | 0.85 kg (1.87 lbs) |
| Length | 142 mm |
| Width | 58 mm |
| Height | 45 mm |
| OEM Reference | ZF 4644.253.050 |
| Thread Type | M12 x 1.5 |
Compatibility
This part is primarily engineered for the ZF WG 158 series, but it also fits several related heavy-duty transmission models. It is compatible with the WG 180, WG 200, and WG 210 series when used in conjunction with the correct SCREW-IN SLEEVE adapter. Additionally, it integrates seamlessly with the GEAR SHIFT HOUSING found in later WG 250 variants. Always verify your transmission serial number before ordering.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4644101190 | TRANSMISSION HOUSING | Encloses and protects internal gear sets and hydraulic circuits |
| 4644159347 | SHIFT SYSTEM | Controls clutch pack engagement and gear selection |
| 4475280036 | SCREW-IN SLEEVE | Secures hydraulic lines and prevents fluid leakage |
| 4644306511 | GEAR SHIFT HOUSING | Houses shift forks and selector mechanisms |
| 4644306440 | PISTON | Applies hydraulic pressure to clutch packs |
| 0635470104 | ROLLER | Reduces friction in shift rail movement |
| 0730006344 | RING | Seals piston bore to prevent cross-leakage |
| 0730006345 | RING | Provides secondary sealing for high-pressure circuits |
| 0730006346 | RING | Dampens vibration in valve body assembly |
| 0730006347 | RING | Retains lubrication within rotating assemblies |
Frequently Asked Questions
Q: How do I know if the 4644.253.050 is the correct replacement for my WG 158?
A: Check the stamped number on your existing part. It should match the SKU exactly. Also verify that your transmission serial number falls within the WG 158 range (typically 158-xxxxx).
Q: Can I install this part without replacing the shift system components?
A: While direct replacement is possible, we strongly recommend inspecting the SHIFT SYSTEM for wear simultaneously, as degraded parts often damage each other over time.
Q: What torque specification should I use for the mounting bolts?
A: Use 45 Nm (33 ft-lbs) for the main housing bolts. Always apply thread locker to the SCREW-IN SLEEVE to prevent loosening under vibration.
📞 Need this part? Contact our ZF specialists:
Email: info@partszf.com |
Phone: +86 158 2286 3467 |
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