Overview
The ZF 4166.028.085 CONVERTER Torque Converter Assembly is a complete, drop-in replacement unit engineered for the WG 100 Series transmission family. This critical component sits between the engine flywheel and the transmission input shaft, functioning as a hydraulic coupling that multiplies engine torque during launch and smoothly transfers power through the drivetrain. The SKU 4166.028.085 is a fully assembled converter, including the impeller, turbine, stator, and lock-up clutch, designed to restore factory-spec performance in heavy-duty industrial applications. When paired with a robust 4651101007: TRANSMISSION HOUSING, this assembly ensures precise alignment and long-term durability under high load cycles.
Symptoms of Failure
- Shudder or vibration during acceleration: A worn torque converter stator or damaged needle bearings cause noticeable shudder when the converter attempts to multiply torque, often felt between 20-40 mph.
- Delayed engagement or gear slipping: Internal seal degradation within the 4166.028.085 leads to low stall speed and a soft, delayed shift from Park to Drive or Reverse, mimicking transmission slip.
- Overheating transmission fluid: A failing lock-up clutch or worn impeller vanes generate excessive heat, causing the ATF to darken and burn, often accompanied by a pungent odor.
- Torque converter drain-back noise: A distinct “gurgling” or “whining” sound at idle indicates a failed one-way clutch or worn bushing, allowing fluid to drain back into the pan.
Technical Specifications
| Part Number | 4166.028.085 |
| Assembly Type | Complete Torque Converter (Impeller, Turbine, Stator, Lock-Up Clutch) |
| Overall Diameter | ~340 mm (13.4 in) |
| Pilot Diameter | ~55 mm |
| Weight | ~18.5 kg (40.8 lbs) |
| Housing Material | High-Strength Cast Aluminum |
| Stall Torque Ratio | 2.0:1 (Nominal) |
| OEM Reference | ZF 4166.028.085 / WG 100 Series |
| Seal Compatibility | Requires 0634303928: O-RING for pump housing seal |
Compatibility
This torque converter assembly is specifically designed for the ZF WG 100 Series, including the WG180, WG200, WG210, and WG250 models commonly found in municipal trucks, refuse vehicles, and industrial loaders. It directly replaces the original converter in these transmissions and requires a compatible 4651301029: HOUSING for proper fitment. For units with a different bellhousing pattern, verify the pilot bore and flexplate bolt circle before installation. The 4166.028.085 also integrates with the 4651301024: HOUSING used in certain WG200 variants.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4651101007 | TRANSMISSION HOUSING | Main structural casing for the transmission assembly |
| 4651301029 | HOUSING | Rear housing adapter for converter clearance |
| 0634303928 | O-RING | Seal between converter hub and pump housing |
| 4651301024 | HOUSING | Front bellhousing for specific WG200 applications |
| 4651203002 | SCREEN SHEET | Fine mesh filter for transmission oil sump |
| 4651303005 | SCREEN SHEET | Coarse debris screen for converter circuit |
| 0636101032 | CAP SCREW | Mounting bolt for housing and bellhousing |
| 0630361028 | SEALING CAP | Protective cap for unused hydraulic ports |
| 4475280060 | SCREW PLUG | Threaded plug for oil gallery access |
| 0634303312 | O-RING | Seal for screw plug and cap screw interfaces |
