Overview
The ZF 4143.020.141 2 HL 290 Hydrostatic Drive Assembly is a complete, pre-assembled unit designed for the HL 100 and HL 270 series transmissions. This assembly integrates the hydraulic pump and motor into a single, sealed module, converting engine power into infinitely variable hydraulic flow for precise vehicle speed and torque control. As a critical power transfer component, the 4143.020.141 sits between the engine bell housing and the transmission gearbox, managing high-pressure oil flow to drive the wheels. This complete unit includes the necessary 4143101043: HOUSING and 4143301055: HOUSING sections, ensuring a direct bolt-on replacement for worn or failed assemblies. The SKU 4143.020.141 is a direct OEM reference for this specific hydrostatic drive configuration.
Symptoms of Failure
When the ZF 4143.020.141 hydrostatic drive assembly begins to fail, operators typically notice these specific symptoms:
- Loss of traction or erratic speed control: The vehicle may surge, hesitate, or fail to maintain a constant speed under load, indicating internal piston or swash plate wear.
- External oil leaks at the housing seams: High-pressure oil seeps past degraded seals, often pooling around the 4143298040: CASE or the output shaft area.
- Excessive noise (whining or grinding): A high-pitched whine during acceleration or a grinding sound when turning signals bearing failure or cavitation within the hydraulic circuit.
- Overheating of the transmission fluid: Internal slippage generates excess heat, causing the system to run hot and potentially triggering warning lights or thermal shutdown.
Technical Specifications
| Part Number | 4143.020.141 |
| Assembly Type | Complete Hydrostatic Drive Unit (2 HL 290) |
| Displacement | 90 cc/rev (estimated) |
| Maximum Pressure | 420 bar (6,100 psi) |
| Weight | 48 kg (106 lbs) approx. |
| Housing Material | High-strength aluminum alloy |
| OEM Reference | ZF 4143.020.141 |
| Mounting Flange | SAE A 2-Bolt |
Compatibility
This hydrostatic drive assembly is engineered for ZF’s HL series transmissions, specifically the HL 100 and HL 270 series. It is a direct fit for models including the WG180, WG200, and WG210 series when configured with a 2 HL 290 hydrostatic unit. The assembly also integrates with earlier WG series transmissions that utilize a separate pump and motor configuration. For proper installation, ensure the 0631329135: SPRING PIN is correctly aligned to secure the control linkage to the swash plate.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4143101043 | HOUSING | Encloses the pump section of the hydrostatic drive |
| 4143301055 | HOUSING | Encloses the motor section of the hydrostatic drive |
| 4143298040 | CASE | Main structural casing for the gearbox interface |
| 0631329135 | SPRING PIN | Secures control linkage to the swash plate |
| 0501214034 | SEALING CAP | Seals the charge pressure port |
| 0636101024 | CAP SCREW | Fastens the housing sections together |
| 4475280099 | SCREW PLUG | Plugs the case drain port |
| 0634303266 | O-RING | Seals the housing interface |
| 4143301045 | SCREEN SHEET | Filters debris from the charge oil |
| 0636420051 | COUNTERSUNK SCREW | Secures the screen sheet in place |
