Overview
The ZF 4644.323.041 PLANET CARRIER is a critical rotating assembly within the WG 180 and WG 200 series transmissions. This OEM genuine component houses the planetary gears and pins, transferring torque from the turbine shaft to the output shaft while managing the high stress of gear reduction. The SKU 4644.323.041 serves as the central hub for the planetary gear set, ensuring precise alignment and load distribution during operation. Without this carrier, the transmission cannot achieve its rated torque capacity or gear ratio stability.
Symptoms of Failure
- Transmission gear slipping under load: A worn planet carrier causes erratic gear engagement, particularly when climbing grades or hauling heavy loads.
- Metallic grinding noise from the transmission housing: Failed needle bearings or cracked carrier arms produce a distinct scraping sound during acceleration or deceleration.
- Oil contamination with metallic debris: Flakes or shavings in the transmission fluid indicate the planet carrier surface is degrading, often leading to blocked oil passages.
- Vibration during gear shifts: Uneven wear on the carrier causes the planetary gears to wobble, transmitting harsh vibrations through the driveline.
Technical Specifications
| Parameter | Value |
|---|---|
| Part Number | 4644.323.041 |
| Material | Case-hardened alloy steel |
| Weight | 4.8 kg (10.6 lbs) |
| Outer Diameter | 185 mm |
| Center Bore | 42 mm |
| Number of Pinion Pockets | 4 |
| OEM Reference | ZF 4644.323.041 |
Compatibility
This planet carrier is engineered for the ZF WG 180 and WG 200 transmission families. It directly replaces the carrier in WG 200 Series units used in municipal buses, construction loaders, and medium-duty trucks. The part also fits select WG 180 variants with a 4-pinion planetary design. Always verify the transmission serial number against the 4644.323.041 casting mark before installation.
During assembly, this carrier interfaces with the 4460165051: CONSOLE and the 4460368311: CONSOLE to secure the planetary assembly. The carrier is fastened using the 0636011429: HEXAGON SCREW and the 0730100365: WASHER to ensure proper torque retention. These components must be replaced together to prevent misalignment and premature wear.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4644105418 | DISCONNECTION | Disconnects torque flow during neutral shifts |
| 4644305041 | ADAPTER | Mounts the transmission to the engine bellhousing |
| 4460068159 | AXLE DRIVE | Transfers power from the differential to the wheels |
| 4460168651 | INPUT FLANGE | Connects the driveshaft to the transmission input |
| 4460368318 | FLANGE | Seals the output shaft and supports the yoke |
| 4460368317 | DUST PROTECTION | Prevents debris ingress at the output seal |
| 4460165051 | CONSOLE | Supports the planetary carrier housing |
| 4460368311 | CONSOLE | Secondary support bracket for the carrier |
| 0636011429 | HEXAGON SCREW | Fastens the carrier to the sun gear shaft |
| 0730100365 | WASHER | Distributes clamping force under the screw head |
