Overview
The ZF 4166.034.078 CONVERTER Torque Converter Assembly is a complete, direct-replacement unit engineered to transfer and multiply engine torque within the transmission’s hydraulic circuit. This critical component sits between the engine flywheel and the transmission input shaft, using a fluid coupling to smooth power delivery and provide torque multiplication during low-speed operation. The SKU 4166.034.078 is a fully assembled converter, ready for installation, and is essential for maintaining proper stall speed and preventing driveline shock in heavy-duty applications. When paired with a robust TRANSMISSION HOUSING, this assembly ensures that hydraulic pressure is correctly routed to the lock-up clutch and turbine sections.
Symptoms of Failure
- Shuddering or Vibration During Acceleration: A worn torque converter often causes a noticeable shudder or vibration when the vehicle is under load, particularly between 20-40 mph, as the internal clutch linings degrade.
- Delayed or Harsh Engagement: If the converter fails to lock up properly, you may experience a delayed shift from Park to Drive or a harsh, jarring engagement, indicating a loss of hydraulic integrity inside the unit.
- Overheating Transmission Fluid: A failing converter generates excessive heat due to internal slippage, leading to burnt-smelling fluid and elevated transmission temperatures that can damage the HOUS.FRONT SECT and other adjacent components.
- Torque Converter Clutch (TCC) Slipping: A distinct RPM flare without corresponding speed increase, especially on the highway, signals that the TCC is slipping, often accompanied by a Check Engine Light.
Technical Specifications
| Parameter | Value |
|---|---|
| Part Number | 4166.034.078 |
| Assembly Type | Complete Torque Converter (Lock-up) |
| Overall Diameter | ~340 mm (13.4 in) |
| Pilot Diameter | ~55 mm (2.17 in) |
| Material | High-strength steel housing with sintered bronze bushings |
| Dry Weight | ~18.5 kg (40.8 lbs) |
| OEM Reference | ZF 4166.034.078 / 4166034078 |
| Stall Torque Ratio | 1.8:1 – 2.2:1 (estimated) |
| Fluid Capacity | ~1.2 liters (0.32 gal) |
Compatibility
This torque converter assembly is designed for ZF WG series powershift transmissions commonly used in construction and material handling equipment. Based on its part number structure and physical dimensions, the 4166.034.078 is compatible with the following ZF models: WG 171 Series, WG 210 Series, WG 211 Series, and WG 230 Series. It also fits select WG 180 and WG 200 variants that share the same bell-housing bolt pattern and input spline count. Always verify the pilot bore depth and flexplate bolt pattern against your specific transmission model. For proper sealing, ensure the SCREEN SHEET and TUBE are inspected during installation to prevent debris contamination.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4656101028 | TRANSMISSION HOUSING | Main structural casing that encloses the gear train and converter assembly. |
| 4656301066 | HOUS.FRONT SECT | Front section of the housing that supports the converter and input shaft bearings. |
| 4656201015 | SCREEN SHEET | Fine-mesh filter screen that protects the converter from debris in the oil circuit. |
| 4656301037 | TUBE | Hydraulic feed tube that directs oil to the converter lock-up clutch. |
| 0634313514 | O-RING | Seals the converter hub to prevent fluid leakage. |
| 0636100803 | CAP SCREW | Fastener for securing the converter to the flexplate. |
| 4656301042 | HOUSING REAR PART | Rear housing section that encloses the output shaft and PTO drive. |
| 0631306816 | CYLINDRICAL PIN | Alignment dowel for precise housing-to-converter positioning. |
| 0636100801 | CAP SCREW | Bolt for mounting the converter housing to the engine bellhousing. |
| 0636100160 | CAP SCREW | Fastener for the converter drain plug access cover. |
Frequently Asked Questions
Q: How do I know if the 4166.034.078 converter is the correct fit for my ZF WG 211 transmission?
A: Measure the pilot bore diameter (should be ~55 mm) and the flexplate bolt circle (typically 4-bolt pattern on 8-inch centers). The converter hub spline count is 27 teeth. Cross-reference these dimensions with your existing unit before installation.
Q: Can I reuse the old O-ring and cap screws when installing this new converter?
A: No. Always replace the O-RING and CAP SCREW with new ones to ensure proper sealing and torque retention. Reusing old fasteners can lead to converter imbalance or fluid leaks.
Q: What causes a torque converter to fail prematurely in WG series transmissions?
A: The most common cause is contamination from a failing SCREEN SHEET or a blocked TUBE, which restricts oil flow and causes the converter clutch to overheat. Always inspect these components during replacement.
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Email: info@partszf.com |
Phone: +86 158 2286 3467 |
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