Overview
The ZF 4143.020.217 2 HL 270 Hydrostatic Drive Assembly is a complete, factory-sealed unit designed to manage variable-speed power delivery in heavy-duty mobile machinery. This assembly integrates the hydraulic pump and motor into a single, robust package, converting engine torque into infinitely variable hydraulic flow for precise vehicle or implement control. As a core component of the HL 270 series, it replaces worn or failed units to restore original performance. The SKU 4143.020.217 is a direct OEM-specified replacement, ensuring exact fitment and hydraulic pressure ratings. When rebuilding a transmission, this drive assembly works in concert with the 4143101050: HOUSING and the 4143301055: HOUSING to form the sealed hydraulic circuit.
Symptoms of Failure
- Erratic or surging drive speed: If the hydrostatic unit cannot maintain consistent flow, the machine may lurch or fail to hold a steady ground speed under load, indicating internal piston or swashplate wear.
- Hydraulic oil overheating: Excessive internal leakage across worn seals or valve plates generates heat, causing the transmission to run hot even during normal operation.
- Loss of traction or creeping: A failing drive assembly may allow the vehicle to drift on inclines or lose pulling power, as the unit cannot maintain static hydraulic pressure.
- External oil seepage from the case: Degraded shaft seals or housing gaskets allow fluid to escape, often pooling around the unit’s mounting flange or output shaft.
Technical Specifications
| Parameter | Specification |
|---|---|
| Part Number | 4143.020.217 |
| Assembly Type | 2 HL 270 Hydrostatic Drive (Complete Unit) |
| Displacement | 270 cc/rev (estimated) |
| Maximum Operating Pressure | 420 bar (6,090 psi) |
| Housing Material | High-strength cast iron |
| Dry Weight | Approx. 85 kg (187 lbs) |
| OEM Reference | ZF 4143.020.217 |
| Seal Kit Compatibility | Includes 0634303266: O-RING |
Compatibility
This hydrostatic drive assembly is engineered for ZF’s HL 100 and HL 270 series transmissions, commonly installed in telehandlers, wheel loaders, and agricultural tractors. It directly replaces units in the WG180 and WG200 power shift transmissions, as well as the ERGOPOWER series where a 270 cc hydrostatic motor is specified. The assembly mounts directly to the 4143298040: CASE and is secured using the 0631329135: SPRING PIN for alignment. Always verify your transmission model’s displacement rating before ordering.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4143101050 | HOUSING | Encloses the pump/motor rotating group |
| 4143301055 | HOUSING | Opposite-side housing for shaft support |
| 4143298040 | CASE | Main structural transmission casing |
| 0631329135 | SPRING PIN | Locks housing alignment dowels |
| 0636101024 | CAP SCREW | Fastens housing halves together |
| 4475280099 | SCREW PLUG | Seals hydraulic test ports |
| 0634303266 | O-RING | Static seal between housing flanges |
| 0501200072 | VENT VALVE | Relieves case internal pressure |
| 0501217673 | LUBRICATING NIPPLE | Grease fitting for spline lubrication |
| 0636302031 | SCREW PLUG | Closes drain or fill openings |
