Overview
The ZF 4656.223.006 TUBE is a critical fluid conduit engineered for the WG191 and WG211 transmission series. This OEM genuine part directs pressurized hydraulic oil to the clutch packs and valve body, ensuring precise shift timing and lubrication within the gear train. As an integral component of the transmission’s hydraulic circuit, it sits between the TRANSMISSION HOUSING and the HOUS.FRONT SECT, where it maintains consistent flow under high thermal loads. The SKU 4656.223.006 is a direct replacement for worn or damaged tubes, restoring factory-specified oil pressure and preventing cross-contamination between circuits.
Symptoms of Failure
- External oil leaks at the tube-to-housing interface: A cracked or corroded tube allows transmission fluid to escape, often pooling near the HOUSING REAR PART.
- Erratic gear engagement or delayed shifts: Reduced hydraulic pressure from a compromised tube causes slipping between gears, especially under load.
- Overheating transmission due to insufficient lubrication: A blocked or deformed tube starves bearings and clutches of oil, leading to thermal distress.
- Contaminated fluid from debris ingress: A fracture in the tube can allow metal particles or dirt to enter the hydraulic system, accelerating wear on valves and seals.
Technical Specifications
| Parameter | Value |
|---|---|
| Part Number (SKU) | 4656.223.006 |
| Material | Steel, zinc-plated for corrosion resistance |
| Length (approx.) | 185 mm |
| Outer Diameter | 12 mm |
| Wall Thickness | 1.5 mm |
| Weight | 0.12 kg |
| OEM Reference | ZF 4656.223.006 |
| Sealing Type | O-ring groove at both ends |
Compatibility
This tube is specifically designed for ZF WG191 and WG211 series transmissions, commonly found in medium-duty trucks, buses, and off-highway equipment. It also fits select variants of the WG180 and WG200 series where the hydraulic circuit layout matches. Always verify the part number against your transmission’s serial plate. For assembly, ensure the tube is seated correctly between the TRANSMISSION HOUSING and the CYLINDRICAL PIN that aligns the front section.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4657101049 | TRANSMISSION HOUSING | Main structural casing for gear sets and shafts |
| 4657301130 | HOUS.FRONT SECT | Front section housing the pump and valve body |
| 4657301131 | HOUSING REAR PART | Rear casing supporting output shaft and bearings |
| 0631306816 | CYLINDRICAL PIN | Alignment dowel for precise housing mating |
| 0636102489 | CAP SCREW | Fastener for securing housing sections |
| 4656301148 | FIXING PLATE | Retains tube and prevents vibration loosening |
| 0636102463 | CAP SCREW | Bolt for front section attachment |
| 4657201133 | SCREEN SHEET | Filter mesh protecting hydraulic circuits |
| 0636115287 | CAP SCREW | High-tensile fastener for rear housing |
| 4657301065 | PLATE | Spacer plate for oil flow distribution |
