Overview
The ZF 4646.109.407 PARKING BRAKE is a critical safety and holding component engineered specifically for the WG 250 Series transmission. This OEM genuine part engages a mechanical locking mechanism on the output shaft, ensuring the vehicle remains stationary when parked or during maintenance. Located within the rear section of the transmission assembly, the parking brake interfaces directly with the TRANSMISSION HOUSING to provide reliable static torque retention. The SKU 4646.109.407 is the exact factory-specification replacement, guaranteeing a precise fit and original performance characteristics for heavy-duty industrial applications.
Symptoms of Failure
- Vehicle roll-away on inclines: A worn parking brake fails to hold the transmission output shaft, causing the vehicle to drift even when the brake is fully engaged.
- Grinding or scraping noises during engagement: Deteriorated friction surfaces or broken return springs produce audible metal-on-metal sounds when the parking brake is applied or released.
- Inconsistent brake release: The lever or actuator becomes stiff or sticks, requiring excessive force to disengage, often accompanied by a sudden “pop” as the mechanism frees itself.
- Oil seepage near the brake housing: Failed seals within the parking brake unit allow transmission fluid to leak past the HOUSING interface, leaving visible drips under the drivetrain.
Technical Specifications
| Parameter | Specification |
|---|---|
| Part Number | 4646.109.407 |
| OEM Reference | ZF 4646.109.407 |
| Material | High-strength alloy steel with sintered friction lining |
| Weight | 2.85 kg (6.28 lbs) |
| Outer Diameter | 210 mm |
| Inner Spline Diameter | 45 mm |
| Operating Temperature Range | -40°C to +120°C |
| Torque Holding Capacity | 1,200 Nm (885 lb-ft) |
Compatibility
This parking brake is primarily designed for the ZF WG 250 Series transmission. Based on its spline configuration and housing geometry, it is also compatible with the following ZF models: WG180, WG200, and WG220. For proper installation, the brake must be paired with the correct COVER and secured using the specified HEXAGON SCREW fasteners. Always verify the output shaft spline count and housing bolt pattern before ordering.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4646101028 | TRANSMISSION HOUSING | Main structural casing that encloses the gear train and brake assembly |
| 4646301095 | HOUSING | Intermediate housing supporting the parking brake and output shaft |
| 4646301087 | COVER | Sealing cover that protects the brake mechanism from contaminants |
| 0636015304 | HEXAGON SCREW | Fastener used to secure the brake assembly to the housing |
| 0636101828 | CAP SCREW | High-tensile bolt for mounting the brake cover |
| 4646301102 | COVER SHEET | Thin protective plate over the brake actuation linkage |
| 4646301098 | COVER SHEET | Secondary cover sheet for dust and debris exclusion |
| 0730365125 | TYPE PLATE | Identification plate riveted to the housing with model and serial data |
| 0631311009 | GROOVED STUD | Alignment stud for precise positioning of the brake assembly |
| 0636101193 | CAP SCREW | Additional fastening bolt for the brake actuator bracket |
