Overview
The ZF 4699.804.095 GK25 II is a genuine OEM gearshift unit designed for heavy-duty construction machinery transmissions. This component serves as the primary actuation mechanism for selecting forward, reverse, and neutral positions within the transmission valve body. Positioned directly on the control housing assembly, the GK25 II converts mechanical lever input into precise hydraulic signals that govern clutch engagement. The SKU 4699.804.095 is a direct replacement for the original factory-installed part, ensuring exact fitment and shift quality. When paired with a robust 4699101112 HOUSING, this unit maintains the structural integrity required for high-torque applications in wheel loaders and graders.
Symptoms of Failure
- Erratic gear engagement or delayed shifting – Worn internal spools in the GK25 II cause hesitation when moving from neutral to drive, often accompanied by a harsh clunk.
- Hydraulic fluid seepage around the shift tower – Degraded seals allow oil to escape past the 4699301193 HOUSING interface, leaving visible drips on the transmission case.
- Inability to hold a selected gear under load – The shift valve fails to maintain hydraulic pressure, causing the machine to slip out of gear during uphill travel or heavy digging.
- Increased lever effort or spongy feel – Internal spring fatigue or contamination reduces mechanical feedback, making gear selection physically demanding.
Technical Specifications
| Parameter | Value |
|---|---|
| Part Number | 4699.804.095 |
| Designation | GK25 II Gearshift Unit |
| Material | Die-cast aluminum alloy with hardened steel spools |
| Weight | 1.8 kg (4.0 lbs) |
| Overall Dimensions | 210 mm x 95 mm x 85 mm |
| OEM Reference | ZF 4699.804.095 |
| Seal Type | Nitrile rubber O-rings (replace with 0634303980 O-RING) |
| Operating Pressure | 12-18 bar (174-261 psi) |
Compatibility
This GK25 II unit is engineered for ZF’s WG series powershift transmissions commonly found in construction equipment. It directly fits the WG180, WG200, and WG210 models used in Volvo, Caterpillar, and Case wheel loaders. The shift pattern and mounting bolt spacing are identical to the original equipment, requiring no adapter plates. For complete assembly, ensure the 4699301015 HOUSING COVER is properly torqued to prevent debris ingress, and verify that the 4699301085 COVER is free of cracks before installation.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4699101112 | HOUSING | Encloses the shift mechanism and provides mounting surface |
| 4699301193 | HOUSING | Secondary housing for valve spool alignment |
| 4699301015 | HOUSING COVER | Seals the top of the shift tower assembly |
| 4699301085 | COVER | Protects shift lever pivot point from contamination |
| 4699301014 | THREAD PROTECTIVE SHIELD | Prevents thread damage during housing installation |
| 0634303980 | O-RING | Hydraulic seal between shift unit and housing |
| 0734307425 | PROTECTION CAP | Covers unused ports to block debris |
| 0501329618 | VENT VALVE | Equalizes internal pressure during temperature changes |
| 0636102023 | CAP SCREW | M10 fastener for housing attachment |
| 0636101008 | CAP SCREW | M8 fastener for cover retention |
