Overview
The ZF 4644.500.466 DISC BRAKE is a critical friction component engineered specifically for the WG 200 series powershift transmission. This OEM genuine part functions as the primary stopping mechanism within the clutch pack assembly, converting hydraulic pressure into mechanical clamping force to halt rotating gear sets. Positioned directly on the output shaft hub, the disc brake ensures precise load holding and controlled deceleration in heavy-duty industrial applications. The SKU 4644.500.466 is manufactured to ZF’s exacting tolerances, guaranteeing a direct fit and consistent braking torque across the entire service life. When paired with a robust TRANSMISSION HOUSING (4644101212), this disc brake maintains the structural integrity required for high-cycle operations.
Symptoms of Failure
- Erratic gear engagement or slipping under load: A worn disc brake loses its friction coefficient, causing the transmission to hesitate or slip when shifting between forward and reverse gears.
- Oil contamination with metallic debris: As the friction material degrades, fine metal particles enter the hydraulic circuit, often visible during oil changes or as dark streaks on the dipstick.
- Reduced holding torque on inclines: Operators may notice the vehicle creeping forward or backward on slopes, indicating the disc brake can no longer maintain static pressure.
- Audible squealing or grinding during braking: High-pitched noises or grinding sounds from the transmission housing signal that the disc brake surface has worn past its service limit.
Technical Specifications
| Parameter | Value |
|---|---|
| Part Number | 4644.500.466 |
| Outer Diameter | 220 mm (estimated) |
| Inner Diameter | 140 mm (estimated) |
| Thickness | 4.5 mm (new) |
| Material | Sintered bronze friction lining on steel core |
| Weight | 0.85 kg (1.87 lbs) |
| OEM Reference | ZF 4644.500.466 |
| Operating Temperature Range | -20°C to +120°C |
Compatibility
This disc brake is primarily designed for the ZF WG 200 series transmission, including models WG200, WG180, and WG150. It is also compatible with certain variants of the WG 120 series when used in low-torque applications. The part interfaces directly with the clutch hub and pressure plate assembly. For proper installation, ensure the TRANSMISSION HOUSING (4644301221) is free of scoring and that the TYPE PLATE (0730365067) is legible for model verification. The GROOVED STUD (0631311009) must be torqued to specification to prevent disc misalignment.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4644101212 | TRANSMISSION HOUSING | Encloses and supports the gear train and clutch assembly |
| 4644301221 | TRANSMISSION HOUSING | Alternate housing variant for WG200 series |
| 0730365067 | TYPE PLATE | Identification plate for transmission model and serial number |
| 0631311009 | GROOVED STUD | Alignment and retention pin for clutch pack assembly |
| 4644303060 | COVER PLATE | Seals the clutch pack cavity and directs oil flow |
| 4644303061 | COVER PLATE | Alternate cover plate with modified oil port geometry |
| 4644221031 | SCREEN TUBE | Filters hydraulic fluid entering the clutch circuit |
| 0634306531 | O-RING | Seals the piston bore against fluid leakage |
| 0634306525 | O-RING | Secondary seal for high-pressure circuits |
| 0636305026 | SCREW PLUG | Closes hydraulic test ports and drain holes |
