Overview
This OEM genuine ZF 4699.803.064 GK20 II is a critical hydraulic control unit designed for heavy-duty construction machinery transmissions. Positioned within the valve body assembly, this component precisely regulates clutch engagement and oil flow to ensure smooth gear shifts under extreme loads. As a direct replacement for the original equipment, the SKU 4699.803.064 guarantees factory-specified tolerances and durability, making it essential for maintaining transmission integrity in excavators, wheel loaders, and graders. Its robust construction resists thermal degradation and hydraulic shock, directly influencing operational uptime.
Symptoms of Failure
When the ZF 4699.803.064 GK20 II begins to wear, operators typically encounter these distinct issues:
- Erratic gear engagement or delayed shifting – A worn control unit fails to modulate hydraulic pressure, causing hesitation or harsh engagement when moving from neutral to drive.
- Internal hydraulic oil leaks – Degraded seals within the unit allow pressurized oil to bypass, leading to visible drips near the transmission housing and a drop in fluid levels.
- Transmission overheating under load – Inefficient oil routing forces the system to work harder, generating excessive heat that triggers warning lights or reduces performance.
- Intermittent slipping in higher gears – As the unit loses calibration, the transmission may momentarily lose torque transfer, particularly during uphill climbs or heavy digging.
Technical Specifications
| Parameter | Value |
|---|---|
| Part Number / SKU | 4699.803.064 |
| Product Designation | GK20 II Control Unit |
| Material Composition | High-grade aluminum alloy with hardened steel spool |
| Overall Dimensions (L x W x H) | 185 mm x 95 mm x 70 mm (approx.) |
| Dry Weight | 1.45 kg (3.2 lbs) |
| OEM Reference | ZF 4699.803.064 (Genuine) |
| Operating Pressure Range | 12–25 bar |
Compatibility
This GK20 II unit is engineered for ZF’s modular transmission families commonly deployed in construction machinery. It is a direct fit for the WG180 and WG200 series, which are standard in many mid-sized loaders and dozers. Additionally, it serves the WG150 and WG250 variants where hydraulic control architecture is shared. Always verify your transmission’s serial number against the OEM parts catalog, as minor revisions in valve body porting may require specific iterations of the 4699.803.064.
