Overview
The ZF 4642.306.048 FILLER PIECE is a precision-engineered spacer component designed for the WG 181 series of heavy-duty transmissions. This OEM genuine part sits within the transmission housing assembly, acting as a critical alignment shim between the TRANSMISSION HOUSING and the HOUSING to maintain correct gear mesh clearances and oil flow paths. The SKU 4642.306.048 ensures exact dimensional tolerances required for proper clutch pack engagement and hydraulic pressure distribution within the WG181 gearbox. Without this filler piece, the transmission’s internal components cannot achieve the precise axial positioning necessary for reliable operation under high torque loads.
Symptoms of Failure
- Oil seepage at housing joint: When the filler piece compresses or deforms over time, transmission fluid can leak between the TRANSMISSION HOUSING and HOUSING mating surfaces, causing visible drips or wet spots on the bell housing.
- Intermittent gear slipping under load: A worn filler piece allows axial play in the shaft assembly, leading to incomplete clutch pack engagement and momentary power loss during acceleration or hill climbing.
- Abnormal whining or grinding noise: Misalignment caused by a degraded filler piece creates uneven gear contact patterns, producing a distinct high-pitched whine that intensifies with vehicle speed.
- Delayed shift engagement: Hydraulic pressure drops due to improper sealing at the filler piece location result in sluggish shifts between forward and reverse gears, particularly in cold operating conditions.
Technical Specifications
| Specification | Value |
|---|---|
| Part Number | 4642.306.048 |
| Material | High-grade steel alloy with corrosion-resistant coating |
| Length | 48 mm |
| Width | 18 mm |
| Thickness | 6.2 mm |
| Weight | 0.085 kg |
| OEM Reference | ZF 4642.306.048 |
| Surface Finish | Ground and polished to Ra 0.8 µm |
Compatibility
This filler piece is specifically engineered for the ZF WG 181 series, but it also fits select models in the WG180 and WG200 transmission families due to shared housing dimensions. The part interfaces directly with the THREADED BUSH and TYPE PLATE within the same assembly. Compatible transmission models include WG180, WG181, WG200, and certain WG210 variants manufactured after 2005. Always verify the existing housing configuration before installation, as the filler piece works in conjunction with the COVER PLATE to maintain proper oil gallery alignment.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4644101047 | TRANSMISSION HOUSING | Main structural casing for gear and shaft assembly |
| 4644301380 | HOUSING | Secondary housing component for clutch pack support |
| 4644301189 | THREADED BUSH | Provides threaded mounting point for filler piece retention |
| 0730365067 | TYPE PLATE | Identification plate with transmission serial number |
| 0631311009 | GROOVED STUD | Alignment stud for precise housing positioning |
| 4644301161 | COVER PLATE | Seals the filler piece cavity against debris ingress |
| 0636100621 | HEXAGON SCREW | Fastener for securing cover plate to housing |
| 0631610020 | SET SCREW | Adjustable locking screw for filler piece tension |
| 0634801098 | SEALING RING | Prevents oil leakage at filler piece interface |
| 4644301117 | FIXING PLATE | Retains filler piece in position during operation |
