Overview
The ZF 4143.020.162 2 HL 270 Hydrostatic Drive Assembly is a complete, pre-assembled unit designed for variable-speed propulsion in heavy-duty industrial vehicles. This SKU 4143.020.162 integrates the axial piston pump and motor within a single housing, converting hydraulic energy into precise mechanical output for ZF HL 100 and HL 270 series transmissions. It sits directly between the engine power take-off and the final drive, regulating torque distribution without mechanical clutch engagement. The assembly includes critical sealing and mounting interfaces, and it is typically paired with the 4143101043: HOUSING to contain hydraulic pressure, while the 4143301055: HOUSING provides the structural base for the swashplate mechanism.
Symptoms of Failure
- Hydrostatic drive slipping under load: When the internal piston bores wear, the unit loses pressure, causing erratic speed control or complete loss of traction during heavy pulling.
- External oil leaks at housing seams: Degraded O-rings or cracked castings allow hydraulic fluid to weep from the joint between the drive assembly and the 4143298040: CASE, leaving puddles under the vehicle.
- Whining or knocking noise during operation: Worn bearings or scored cylinder blocks generate metallic sounds, especially when the transmission shifts from forward to reverse.
- Overheating of the transmission fluid: Internal bypassing due to failed valve plates causes excessive heat buildup, triggering thermal shutdowns in the hydraulic circuit.
Technical Specifications
| Parameter | Value |
|---|---|
| Part Number | 4143.020.162 |
| Assembly Type | 2 HL 270 Hydrostatic Drive (Complete Unit) |
| Displacement | 270 cc/rev (estimated) |
| Maximum Pressure | 420 bar (6,090 psi) |
| Housing Material | High-strength cast iron |
| Dry Weight | Approx. 85 kg (187 lbs) |
| OEM Reference | ZF 4143.020.162 |
| Sealing System | Includes 0634303266: O-RING and 0501214034: SEALING CAP |
| Fastener Torque | Uses 0636101024: CAP SCREW and 4475280099: SCREW PLUG |
Compatibility
This hydrostatic drive assembly is engineered for ZF HL 100 and HL 270 series transmissions, commonly found in agricultural tractors, wheel loaders, and telehandlers. It directly replaces units in WG180, WG200, and WG250 models where a 270 cc hydrostatic loop is specified. The assembly requires the 0631329135: SPRING PIN for alignment during installation. It also interfaces with the 4143301045: SCREEN SHEET for filtration and the 0636420051: COUNTERSUNK SCREW for securing the valve plate. Always verify your transmission model number before ordering.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4143101043 | HOUSING | Encloses the hydrostatic pump and motor assembly |
| 4143301055 | HOUSING | Supports swashplate and control piston |
| 4143298040 | CASE | Outer structural shell for the transmission |
| 0631329135 | SPRING PIN | Locates and aligns drive assembly to case |
| 0501214034 | SEALING CAP | Prevents fluid loss from test ports |
| 0636101024 | CAP SCREW | Secures housing flanges |
| 4475280099 | SCREW PLUG | Closes hydraulic passages |
| 0634303266 | O-RING | Seals between housing and drive unit |
| 4143301045 | SCREEN SHEET | Filters debris from hydraulic fluid |
| 0636420051 | COUNTERSUNK SCREW | Fastens valve plate to housing |
