Overview
The ZF 4699.841.008 GK26LD is an OEM genuine hydraulic control valve assembly engineered for the precise modulation of clutch packs within ZF heavy-duty powershift transmissions. This component governs the flow and pressure of transmission fluid to engage and disengage gears, acting as the central command unit for shift quality. The SKU 4699.841.008 is a direct replacement part designed to restore factory-spec performance in construction machinery drivelines. It interfaces directly with the valve body housing and is secured by the 4699101086 HOUSING and the 4699301223 HOUSING, which provide the structural foundation for the assembly.
Symptoms of Failure
- Delayed or harsh gear engagement: When the 4699.841.008 valve spools wear, hydraulic pressure bleeds off, causing a noticeable lag when shifting from neutral to drive or reverse.
- Transmission fluid leaks at the valve body: Worn sealing surfaces or internal O-rings allow ATF to escape, often pooling around the transmission pan or bell housing.
- Erratic shifting under load: The transmission may slip between gears or hunt for the correct ratio during uphill operation or heavy digging cycles.
- No forward or reverse movement: Complete hydraulic failure of the valve can prevent clutch pack pressurization, leaving the machine immobilized despite engine power.
Technical Specifications
| Parameter | Value |
|---|---|
| Part Number | 4699.841.008 (GK26LD) |
| Material | High-strength aluminum alloy with hardened steel spools |
| Weight | Approx. 4.2 kg (9.3 lbs) |
| Dimensions (L x W x H) | 280 mm x 180 mm x 95 mm |
| OEM Reference | ZF 4699.841.008 |
| Operating Pressure | 12–18 bar (174–261 psi) |
| Seal Type | Nitrile rubber (NBR) static seals |
Compatibility
This valve assembly is primarily designed for ZF WG180, WG200, and WG211 powershift transmissions commonly found in wheel loaders, telehandlers, and graders. It is also compatible with select ZF 4WG-200 and 6WG-200 series units used in construction machinery from manufacturers such as Liebherr, Volvo, and JCB. Always verify the transmission serial number against the SKU 4699.841.008 before installation.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4699101086 | HOUSING | Encloses the valve assembly and provides mounting points |
| 4699301223 | HOUSING | Secondary housing for hydraulic passage routing |
| 0636302022 | SCREW PLUG | Seals test ports and fluid channels |
| 0501319149 | SCREW PLUG | Magnetic drain plug for debris collection |
| 0634801038 | SEALING RING | Prevents fluid bypass at plug interfaces |
| 0730365801 | TYPE PLATE | Identification plate with transmission specs |
| 0501323165 | SHAFT SEAL | Dynamic seal for rotating shafts |
| 4699301222 | COVER | Protects valve body from contamination |
| 0634303996 | O-RING | Static seal between housing sections |
| 0630513060 | SNAP RING | Retains internal components in position |
