Overview
The ZF 4699.803.067 GK20 II is a genuine OEM shift cylinder assembly, a critical hydraulic actuation component within the transmission control system. This part is responsible for engaging and disengaging specific gear sets by directing pressurized oil to the clutch packs. Positioned inside the valve body or directly on the transmission housing, the SKU 4699.803.067 converts hydraulic signals from the control unit into precise mechanical movement. When this cylinder fails, the entire gear selection process becomes compromised, leading to operational delays and potential drivetrain damage in heavy construction machinery.
Symptoms of Failure
Recognizing the early signs of a worn ZF 4699.803.067 can prevent costly downtime. The following failure modes are commonly reported:
- Erratic gear engagement or delayed shifting: The machine hesitates or jerks violently when moving from neutral into forward or reverse, indicating insufficient hydraulic pressure from the cylinder.
- Internal oil leaks and fluid loss: Worn piston seals cause transmission fluid to bypass the cylinder, leading to visible drips near the valve body and a gradual drop in the oil level.
- Inability to hold a selected gear under load: The transmission slips out of gear when the machine is under heavy strain, such as during digging or pushing operations, due to the cylinder failing to maintain clamping force.
- Erratic shift patterns or harsh engagement: The transmission may unexpectedly shift into a different gear or produce a loud clunking noise during operation, a direct result of the cylinder sticking or failing to stroke fully.
Technical Specifications
| Parameter | Specification |
|---|---|
| Part Number (SKU) | 4699.803.067 |
| Product Designation | GK20 II Shift Cylinder Assembly |
| Material | High-tensile aluminum alloy body with hardened steel piston |
| Weight | Approximately 1.8 kg (3.97 lbs) |
| Overall Length | 195 mm |
| Piston Diameter | 38 mm |
| OEM Reference | ZF 4699.803.067 (Genuine) |
| Seal Kit Compatibility | ZF 0501.302.xxx series |
Compatibility
This genuine ZF 4699.803.067 shift cylinder is engineered for use in specific ZF power shift transmissions commonly found in wheel loaders, telehandlers, and graders. Based on its design and hydraulic flow characteristics, it is compatible with the following transmission models:
- ZF WG180 (all series variants)
- ZF WG200 (including WG200 II and WG200 III)
- ZF 4WG-180 and ZF 4WG-200 (four-speed versions)
- ZF 6WG-180 and ZF 6WG-200 (six-speed versions)
This part is not interchangeable with the GK20 I variant (SKU 4699.803.066) due to differences in the piston stroke and port configuration. Always verify your transmission serial number against the OEM parts catalog before installation.
