Overview
This genuine OEM part, the ZF 4657.026.011, serves as a critical internal component within the WG 190 Series transmission. It is specifically designed to manage hydraulic flow and pressure regulation, ensuring precise clutch engagement and smooth power delivery. The SKU 4657.026.011 sits within the valve body assembly, acting as a control interface between the transmission housing and the hydraulic circuits. When functioning correctly, it maintains consistent oil pressure, preventing erratic shifting and reducing thermal stress on adjacent components. This part is engineered to ZF’s exacting tolerances, making it a direct replacement for worn units in heavy-duty applications.
Symptoms of Failure
When the ZF 4657.026.011 begins to degrade, operators often notice distinct performance issues. Look for these specific failure symptoms to diagnose the problem early:
- Delayed or harsh gear engagement: A worn valve can cause a noticeable lag when shifting from neutral to drive or reverse, followed by a jarring engagement.
- Erratic shift timing: The transmission may upshift or downshift at unpredictable RPMs, often hunting for the correct gear under load.
- Internal hydraulic leaks: Degraded sealing surfaces allow pressurized oil to bypass, leading to low line pressure and potential clutch slippage during acceleration.
- Overheating transmission fluid: Constant pressure loss forces the pump to work harder, generating excessive heat and accelerating fluid breakdown.
Technical Specifications
| Specification | Detail |
|---|---|
| Part Number (SKU) | 4657.026.011 |
| Material | Hardened steel with corrosion-resistant coating |
| Weight | 0.85 kg (1.87 lbs) |
| Dimensions (L x W x H) | 95 mm x 45 mm x 30 mm |
| OEM Reference | ZF 4657.026.011 (Genuine) |
| Operating Pressure Range | 8–18 bar |
Compatibility
This genuine ZF 4657.026.011 is primarily designed for the WG 190 Series transmission family. It is also compatible with the WG180 and WG200 models that share the same hydraulic control architecture. Additionally, it can be used in select WG 150 and WG 210 variants where the valve body configuration matches. Always verify your transmission’s serial number against ZF’s compatibility charts before installation.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4657101033 | TRANSMISSION HOUSING | Encloses and supports all internal transmission components |
| 4657201027 | HOUS.FRONT SECT | Front section housing for torque converter and pump assembly |
| 4657201012 | HOUSING REAR PART | Rear housing section supporting output shaft and bearings |
| 0631306792 | CYLINDRICAL PIN | Alignment pin for precise housing assembly |
| 0636100801 | CAP SCREW | Fastener for securing housing sections |
| 4656301148 | FIXING PLATE | Retains valve body components in position |
| 4657301032 | SCREEN SHEET | Fine mesh filter for hydraulic fluid |
| 4657301033 | SCREEN SHEET | Secondary mesh filter for oil return circuit |
| 0636100803 | CAP SCREW | High-torque fastener for valve body mounting |
| 4681301040 | OIL FEED.HOUSG. | Distributes pressurized oil to clutch packs |
Frequently Asked Questions
Q: Can I install the ZF 4657.026.011 without replacing the TRANSMISSION HOUSING?
A: Yes, this part is a standalone replacement. However, if the TRANSMISSION HOUSING shows scoring or cracks, it should be replaced simultaneously to ensure proper sealing and alignment.
Q: What causes premature failure of this valve component?
A: Contaminated transmission fluid is the primary cause. Debris can score the valve bore, leading to sticking. Always replace the SCREEN SHEET filters during service to prevent debris circulation.
Q: Is this part interchangeable between WG190 and WG180 transmissions?
A: Generally yes, but verify the HOUSING REAR PART configuration. Some WG180 units use a different bolt pattern for the valve body, requiring the CAP SCREW set from your original model.
📞 Need this part? Contact our ZF specialists:
Email: info@partszf.com |
Phone: +86 158 2286 3467 |
Request a Quote →
