Overview
The ZF 4699.025.168 GP25 is a genuine OEM gear pump assembly engineered for high-pressure hydraulic circuits within ZF construction machinery transmissions. This component is the primary hydraulic power source, delivering precise oil flow to actuate clutch packs and lubrication channels. The SKU 4699.025.168 mounts directly to the transmission housing and interfaces with the input shaft drive gear. As a critical wear item, it ensures consistent pressure for gear engagement. For proper sealing and alignment, this pump is installed alongside the 4699101165 HOUSING and the 4699301249 HOUSING, which form the pump cavity.
Symptoms of Failure
- Delayed gear engagement or slipping under load: When the GP25 loses volumetric efficiency, hydraulic pressure drops, causing hesitation when shifting from neutral to drive or reverse in wheel loaders and dozers.
- Audible whining or cavitation noise from the transmission: Worn internal gears or a scored housing cover allow air ingestion, producing a high-pitched sound during acceleration.
- External oil seepage at the pump mounting flange: Degraded seals or a cracked 4699309122 HOUSING COVER permit fluid to escape, leaving visible drips under the machine.
- Erratic or low transmission oil pressure readings: A failing pump cannot maintain rated pressure, often triggering warning lamps on the instrument cluster.
Technical Specifications
| Parameter | Value |
|---|---|
| Part Number / SKU | 4699.025.168 |
| Designation | GP25 Gear Pump |
| Material | Hardened alloy steel gears with aluminum housing |
| Displacement (estimated) | 25 cc/rev |
| Maximum Operating Pressure | 25 bar (360 psi) |
| Weight | Approx. 3.2 kg (7.1 lbs) |
| OEM Reference | ZF 4699.025.168 |
| Mounting Hardware | Requires 0636101411 CAP SCREW (4x) |
Compatibility
This GP25 pump is designed for ZF WG series powershift transmissions commonly found in construction machinery. It is a direct fit for the WG180, WG200, and WG220 models used in loaders, graders, and compactors. The pump also appears in certain Ecomat 4HP and 6HP off-highway variants. Always verify the pump cavity dimensions and drive tang configuration against your specific transmission serial number.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4699101165 | HOUSING | Main pump body casting |
| 4699301249 | HOUSING | Intermediate pump housing section |
| 4699309122 | HOUSING COVER | End cover sealing the pump cavity |
| 0636101411 | CAP SCREW | Fastener for housing assembly |
| 0631302072 | CYLINDRICAL PIN | Alignment dowel for housing halves |
| 0636302013 | SCREW PLUG | Port plug for pressure test point |
| 0501331653 | SCREW PLUG | Drain plug for pump cavity |
| 0634801038 | SEALING RING | O-ring for plug sealing |
| 0637885612 | BREATHER | Pressure equalization valve |
| 0769100082 | TYPE PLATE | Identification label for pump assembly |
