Overview
The ZF 4699.170.055 MOTOR is a critical hydraulic drive component engineered for integration within ZF’s heavy-duty powershift transmission assemblies, specifically those deployed in construction machinery. This OEM genuine part converts hydraulic pressure into mechanical torque to actuate clutch packs and shift elements. The SKU 4699.170.055 is positioned as the primary motive force within the valve body and clutch housing circuit, directly interfacing with the 4699100020: BASIC PARTS kit to ensure precise oil flow regulation. Without this motor, the transmission cannot engage or disengage gears under load, making it essential for loader, dozer, and excavator drivelines.
Symptoms of Failure
- Intermittent gear engagement delay or “shift hesitation” — When the motor loses internal seal integrity, hydraulic pressure drops, causing a noticeable lag between lever movement and gear engagement.
- Oil contamination from internal wear debris — As the motor’s rotor and stator surfaces degrade, metallic particles enter the hydraulic circuit, often detected during routine oil analysis.
- Audible whining or grinding from the transmission housing — A failing motor produces high-pitched noise under load, particularly during cold starts or low-RPM operation.
- Complete loss of forward or reverse drive — Advanced wear can cause the motor to seize or fail to build sufficient pressure, resulting in a no-move condition despite engine running.
Technical Specifications
| Parameter | Value |
|---|---|
| Part Number | 4699.170.055 |
| Type | Hydraulic Drive Motor (Gear-Type) |
| Displacement | 28.5 cc/rev (estimated) |
| Maximum Operating Pressure | 250 bar (3,625 psi) |
| Material | Hardened Steel Rotor / Aluminum Alloy Housing |
| Weight | 4.2 kg (9.3 lbs) |
| OEM Reference | ZF 4699.170.055 (Genuine) |
| Mounting Flange | SAE A 2-Bolt (82 mm pilot) |
Compatibility
This motor is designed for ZF’s WG-series powershift transmissions commonly found in construction machinery. It is a direct fit for the WG180, WG200, and WG250 models, as well as the 4WG-200 and 5WG-180 variants. The part also cross-references with select Ergopower and Ecomix drivelines used in telehandlers and wheel loaders. For proper assembly, this motor mounts directly to the 4699300136: HOUSING and drives the 4699300155: WHEEL SHAFT through a splined interface. The 4699300127: PLANET CARRIER must be inspected for wear when replacing this motor, as debris from a failed motor can damage planetary gear sets.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4699100020 | BASIC PARTS | Seal and gasket kit for motor mounting |
| 4699300136 | HOUSING | Encloses motor and directs oil flow |
| 4699300155 | WHEEL SHAFT | Output shaft driven by motor torque |
| 4699300127 | PLANET CARRIER | Holds planetary gears for speed reduction |
| 4699300098 | INNER DISK CARRIER | Supports clutch friction disks |
| 4699200011 | RING GEAR | Outer gear for planetary set |
| 4699300152 | TOOTHED DISC | Torque transfer element |
| 4699300153 | RING GEAR | Secondary ring gear for high-range |
| 4699300154 | RING | Retaining ring for motor shaft |
| 4699300128 | PLANETARY GEAR | Individual gear within planet carrier |
