Overview
The ZF 4699.804.112 GK25 II is a precision-engineered OEM genuine component designed for the power take-off (PTO) assembly within heavy-duty construction machinery transmissions. This part functions as a critical interface between the engine and auxiliary hydraulic systems, ensuring reliable torque transfer for equipment such as wheel loaders, excavators, and graders. As part of the GK25 II series, the SKU 4699.804.112 integrates directly with the 4699004105 GK25 II assembly, where it manages rotational force distribution. Its robust construction withstands high cyclic loads common in earthmoving operations, making it essential for maintaining operational uptime in demanding environments.
Symptoms of Failure
- Oil leaks around the PTO housing: Worn seals or gaskets in the 4699.804.112 unit often cause hydraulic fluid seepage, visible as drips near the transmission bell housing. This symptom is frequently searched as “ZF transmission oil leak from PTO” and indicates imminent seal failure.
- Intermittent gear slipping under load: When the GK25 II component wears, operators may notice momentary loss of power to auxiliary pumps during heavy digging or lifting, commonly described as “PTO slipping when engaging hydraulics.”
- Unusual grinding or whining noises: Bearing degradation within the 4699.804.112 produces metallic sounds that intensify with engine RPM, often flagged in diagnostic searches as “whining noise from ZF transmission PTO.”
- Reduced hydraulic system pressure: A failing part can cause insufficient oil flow to implements, leading to slow boom or bucket response—a symptom often queried as “low hydraulic pressure ZF construction machinery.”
Technical Specifications
| Parameter | Value |
|---|---|
| Part Number (SKU) | 4699.804.112 |
| OEM Reference | GK25 II |
| Material | Hardened alloy steel with corrosion-resistant coating |
| Weight | 4.2 kg (9.26 lbs) |
| Dimensions (L x W x H) | 185 mm x 95 mm x 75 mm |
| Operating Temperature Range | -20°C to +120°C |
| Torque Capacity | 450 Nm (332 ft-lbs) |
| Seal Type | Double-lip nitrile rubber |
Compatibility
This genuine ZF 4699.804.112 GK25 II component is engineered for use in the following ZF transmission models commonly deployed in construction machinery:
- ZF WG180 – Used in mid-size wheel loaders and telehandlers
- ZF WG200 – Found in heavy excavators and graders
- ZF WG150 – Compatible with compact construction equipment
- ZF 4WG-200 – Powers articulated dump trucks and large loaders
When replacing this part, always verify the housing integrity by inspecting the 4699101025 HOUSING for cracks. Additionally, the 4699102063 INPUT shaft and 4699103062 OUTPUT flange should be checked for wear to ensure complete assembly reliability.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4699004105 | GK25 II | Main PTO assembly housing |
| 4699101025 | HOUSING | Outer casing for gear support |
| 4699102063 | INPUT | Drive shaft connection to engine |
| 4699103062 | OUTPUT | Flange for hydraulic pump coupling |
| 4699105045 | TURNTABLE BEARING | Rotary support for PTO engagement |
| 4699301078 | HOUSING | Secondary housing for gear reduction |
| 4699301015 | HOUSING COVER | Seals internal components from debris |
| 4699301085 | COVER | Protects output shaft splines |
| 4699301014 | THREAD PROTECTIVE SHIELD | Prevents thread damage during installation |
| 0634303980 | O-RING | Hydraulic seal between mating surfaces |
