Overview
The ZF 4143.020.268 2 HL 290 Hydrostatic Drive Assembly is a complete, pre-assembled unit designed for the HL 100 and HL 270 series transmissions. This critical component converts hydraulic pressure into mechanical torque, enabling precise speed control and smooth directional changes in heavy-duty industrial machinery. As a complete unit, it eliminates the need for separate component sourcing, reducing downtime during rebuilds. The SKU 4143.020.268 is the direct OEM replacement for the original hydrostatic drive, ensuring a perfect fit within the transmission housing. When paired with the 4143101046 HOUSING and the 4143301055 HOUSING, this assembly forms the core of the hydraulic circuit, delivering reliable power transfer under extreme loads.
Symptoms of Failure
- Erratic machine movement or jerking: When the hydrostatic drive wears, internal piston leakage causes uneven pressure, leading to sudden lurches during acceleration or deceleration.
- Oil leaks near the drive shaft seal: Degraded seals allow hydraulic fluid to escape, often visible as puddles under the transmission bell housing.
- Loss of torque under load: A failing unit cannot maintain high pressure, resulting in sluggish operation when climbing grades or lifting heavy loads.
- Excessive whining or grinding noise: Worn bearings or scored cylinder blocks produce metallic sounds, especially during cold starts or low-speed operation.
Technical Specifications
| Parameter | Specification |
|---|---|
| Part Number | 4143.020.268 |
| Assembly Type | Complete Hydrostatic Drive Unit |
| Displacement | 2 x 290 cc/rev (dual pump) |
| Maximum Pressure | 420 bar (6,090 psi) |
| Input Speed Range | 1,200 – 2,800 RPM |
| Weight | Approx. 48 kg (106 lbs) |
| Housing Material | High-strength aluminum alloy |
| OEM Reference | ZF 2 HL 290 |
| Seal Type | Viton (FKM) O-rings |
Compatibility
This hydrostatic drive assembly is engineered for ZF’s HL 100 and HL 270 series transmissions, which are commonly found in telehandlers, forklifts, and compact construction equipment. It directly replaces units in the WG180, WG200, and WG210 transfer cases. The assembly also integrates with the 4143298040 CASE and requires the 0631329135 SPRING PIN for proper alignment during installation. Always verify your transmission model number before ordering to ensure compatibility with the 2 HL 290 configuration.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4143101046 | HOUSING | Encloses the hydrostatic drive assembly |
| 4143301055 | HOUSING | Secondary housing for valve block |
| 4143298040 | CASE | Main transmission case structure |
| 0631329135 | SPRING PIN | Secures drive shaft alignment |
| 0501214034 | SEALING CAP | Prevents fluid ingress |
| 0636101024 | CAP SCREW | Fastens housing sections |
| 4475280099 | SCREW PLUG | Seals test ports |
| 0634303266 | O-RING | Hydraulic seal between components |
| 0501200072 | VENT VALVE | Relieves case pressure |
| 0501217673 | LUBRICATING NIPPLE | Grease fitting for bearings |
