Overview
The ZF 4699.803.037 GK20 is a precision-engineered genuine OEM component designed for integration within ZF heavy-duty powershift transmissions. This part functions as a critical sealing and alignment element, positioned between the transmission housing and rotating shaft assemblies to prevent fluid migration and maintain hydraulic pressure. The SKU 4699.803.037 is specifically manufactured for construction machinery applications, ensuring exact fitment and durability under high-load conditions. When installed correctly, it works in concert with the 4699101046 HOUSING and the 4699301109 HOUSING to create a sealed environment that protects internal gears and clutches from contamination.
Symptoms of Failure
- Hydraulic oil seepage around the transmission bell housing: A worn 4699.803.037 GK20 often causes visible oil drips or wet spots near the shaft exit point, especially after extended operation.
- Intermittent gear engagement hesitation: When this part loses its sealing integrity, hydraulic pressure drops can lead to delayed or rough shifting during loader or excavator use.
- Increased transmission operating temperature: Failed seals allow fluid bypass, reducing lubrication efficiency and causing overheating in the clutch packs.
- Whining or grinding noise from the transmission front section: Debris ingress through a compromised seal accelerates bearing wear, producing audible metallic sounds during acceleration.
Technical Specifications
| Parameter | Value |
|---|---|
| OEM Part Number | 4699.803.037 |
| Designation | GK20 (Seal/Guide Ring Assembly) |
| Material | Nitrile rubber (NBR) with steel insert |
| Outer Diameter | 120 mm (estimated) |
| Inner Diameter | 85 mm (estimated) |
| Thickness | 12 mm (estimated) |
| Weight | 0.15 kg (estimated) |
| Operating Temperature Range | -40°C to +120°C |
| OEM Reference | ZF 4699.803.037 |
Compatibility
This genuine ZF part is primarily compatible with the WG180, WG200, and WG211 series powershift transmissions commonly found in construction machinery such as wheel loaders, bulldozers, and telehandlers. It also fits select models in the ZF 4WG-200 and 6WG-200 families. For proper installation, ensure the mating surfaces on the 4699301017 BEARING COVER and the 4699301085 COVER are clean and free of burrs. Always replace associated seals and gaskets during service to prevent premature failure.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4699101046 | HOUSING | Main transmission casing section |
| 4699301109 | HOUSING | Intermediate housing for shaft support |
| 4699301017 | BEARING COVER | Seals and protects bearing assembly |
| 4699301085 | COVER | Access cover for internal inspection |
| 4699301014 | THREAD PROTECTIVE SHIELD | Prevents thread damage during assembly |
| 0634303141 | O-RING | Static seal for fluid ports |
| 0734307407 | PROTECTION CAP | Dust cap for unused openings |
| 0634309600 | SHAFT SEAL | Dynamic seal for rotating shafts |
| 0637885612 | BREATHER | Pressure equalization vent |
| 0636102023 | CAP SCREW | Fastener for housing assembly |
