Overview
The ZF 4143.000.191 2 HL 100 Hydrostatic Drive Assembly is a complete, factory-sealed unit engineered for precise power distribution in ZF’s HL 100 and HL 270 series transmissions. This assembly integrates the hydrostatic motor and pump components into a single, ready-to-install package, eliminating the need for separate sub-assembly. The SKU 4143.000.191 serves as the core hydraulic drive element, converting engine power into variable-speed output for demanding off-highway applications. When rebuilding a transmission, this complete unit is often paired with the 4143101009: HOUSING to secure the internal gear train, while the 4143301025: HOUSING provides the necessary sealing surface for the drive shaft.
Symptoms of Failure
Operators experiencing “ZF hydrostatic drive slipping under load” or “HL 100 transmission overheating” should inspect this assembly. Three primary failure indicators include:
- Erratic speed control: The vehicle surges or fails to maintain a constant speed during operation, often due to internal piston wear.
- External oil seepage: Hydraulic fluid pools around the drive assembly flanges, frequently caused by a degraded 0634313603: O-RING that loses its compression seal over time.
- Metallic noise in neutral: A grinding or whining sound when the transmission is disengaged, indicating bearing or swashplate damage within the 4143.000.191 unit.
- Reduced torque output: The machine struggles to climb inclines or move heavy loads, a classic sign of internal leakage past the cylinder block.
Technical Specifications
| Parameter | Value |
|---|---|
| Part Number | 4143.000.191 |
| Assembly Type | Hydrostatic Drive (Complete Unit) |
| Displacement | 100 cc/rev (estimated) |
| Maximum Pressure | 420 bar (6,090 psi) |
| Dry Weight | 34.5 kg (76.1 lbs) |
| Housing Material | High-tensile cast iron |
| OEM Reference | ZF 4143.000.191 |
| Seal Type | Viton (FKM) O-rings |
Compatibility
This hydrostatic drive assembly is primarily designed for ZF’s WG180, WG200, and WG210 series transmissions, where it functions as the primary variable-speed element. It also fits select HL 270 series units when used with the correct adapter plate. The 4143.000.191 is a direct replacement for earlier 2 HL 100 variants and requires the 4475280018: SCREW PLUG to seal the pressure test port during installation. For complete sealing integrity, always replace the 0634313603: O-RING and inspect the 4143101009: HOUSING for scoring before assembly.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4143101009 | HOUSING | Encloses the gear train and supports the drive shaft |
| 4143301025 | HOUSING | Provides sealing surface for the hydrostatic unit |
| 0634313603 | O-RING | Seals the drive assembly to the housing |
| 4475280018 | SCREW PLUG | Seals pressure test port on the assembly |
| 0501342341 | SUPPORT RING | Prevents O-ring extrusion under high pressure |
| 4143298457 | SEAL KIT | Complete set of seals for overhaul |
| 0634313591 | O-RING | Seals the charge pump cover |
| 0636101068 | CAP SCREW | Fastens the drive assembly to the housing |
| 4143221013 | THROTTLE VALVE | Controls hydraulic flow to the drive unit |
| 0634304484 | O-RING | Seals the throttle valve connection |
