Overview
The ZF 4644.323.025 BUSH for WG200 is a precision-engineered wear component designed to maintain correct shaft alignment and reduce friction within the WG 200 series transmission housing. This OEM genuine part, identified by SKU 4644.323.025, acts as a sacrificial liner between rotating shafts and stationary bores, ensuring consistent oil film distribution and preventing metal-on-metal contact. Installed directly in the clutch drum or planetary carrier assembly, this bushing is critical for sustaining torque transfer efficiency under heavy-duty commercial vehicle loads.
Symptoms of Failure
When the 4644.323.025 bushing deteriorates, operators typically notice three distinct failure modes:
- Low-pressure oil leaks around the clutch housing – Worn bushings allow pressurized transmission fluid to bypass seals, often visible as drips near the bell housing.
- Intermittent gear slipping under load – Excessive bushing clearance causes shaft wobble, leading to delayed clutch pack engagement and power loss during acceleration.
- Metallic grinding noise during gear changes – Degraded bushing material produces fine metal particles in the oil, creating audible chatter from the planetary gearset.
- Erratic shift timing – Worn bushings alter hydraulic circuit backpressure, causing harsh or delayed shifts in the WG200 transmission.
Technical Specifications
| Parameter | Value |
|---|---|
| Part Number | 4644.323.025 |
| Material | Sintered bronze with PTFE lining |
| Inner Diameter | 38.10 mm (1.500 in) |
| Outer Diameter | 44.45 mm (1.750 in) |
| Length | 25.40 mm (1.000 in) |
| Weight | 0.045 kg (0.099 lbs) |
| OEM Reference | ZF 4644.323.025 |
| Hardness | HRB 75-85 |
Compatibility
This bushing is specifically engineered for the ZF WG200 series transmission family. It is directly compatible with WG180, WG200, and WG210 models used in municipal buses, refuse trucks, and medium-duty construction vehicles. The 4644.323.025 also fits select ZF Ecomat 4HP and 5HP variants when installed in the rear planetary carrier position. Always verify shaft diameter before ordering.
During replacement, technicians commonly install this bushing alongside the 4460165051: CONSOLE to stabilize the valve body, and the 4460368311: CONSOLE for additional housing support. Secure the assembly using the 0636011429: HEXAGON SCREW and a new 0730100365: WASHER to prevent fastener loosening from vibration.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4644105418 | DISCONNECTION | Clutch pack separation mechanism |
| 4644305041 | ADAPTER | Housing-to-bellhousing interface |
| 4460068159 | AXLE DRIVE | Output shaft power transfer |
| 4460168651 | INPUT FLANGE | Torque converter connection |
| 4460368318 | FLANGE | Driveline mounting point |
| 4460368317 | DUST PROTECTION | Contaminant seal for shaft |
