Overview
The ZF 4646.251.047 DISC CARRIER is a critical internal component engineered for the WG 251 series of heavy-duty automatic transmissions. This OEM genuine part functions as the central hub that supports and aligns the clutch disc packs, ensuring precise torque transfer and smooth gear engagement. Located within the main gear train assembly, the disc carrier interfaces directly with the TRANSMISSION HOUSING to maintain proper axial clearance and rotational stability. The SKU 4646.251.047 is manufactured to ZF’s exacting tolerances, making it essential for maintaining factory-specified shift quality and load capacity in commercial vehicle applications.
Symptoms of Failure
When the ZF 4646.251.047 DISC CARRIER begins to wear, operators may notice several distinct failure indicators. Delayed or harsh gear engagement is a primary symptom, as a worn carrier fails to hold clutch packs in proper alignment, causing erratic shifting. Metallic grinding noises from the transmission housing often occur when the carrier’s splines or bearing surfaces degrade, allowing metal-on-metal contact. Progressive loss of torque under load is another common issue, particularly during uphill climbs or heavy hauling, as the disc carrier can no longer maintain clamping force. Finally, visible metal debris in the transmission fluid during routine checks signals advanced wear of the carrier’s hardened surfaces, requiring immediate replacement to prevent cascading damage to the HOUSING and adjacent components.
Technical Specifications
| Parameter | Specification |
|---|---|
| Part Number | 4646.251.047 |
| Material | Forged alloy steel, induction-hardened |
| Outer Diameter | 180 mm (estimated) |
| Inner Diameter | 95 mm (estimated) |
| Thickness | 28 mm (estimated) |
| Weight | 2.4 kg (estimated) |
| OEM Reference | ZF 4646.251.047 (Genuine) |
| Surface Finish | Ground and phosphate-coated |
Compatibility
This disc carrier is specifically designed for the ZF WG 251 transmission series, but its application extends to several related heavy-duty models. The 4646.251.047 is directly compatible with the WG 180, WG 200, and WG 250 series transmissions that share the same clutch pack architecture. It also fits select variants of the WG 300 series when used with the appropriate COVER assembly. For proper installation, always pair this carrier with new CAP SCREW fasteners to ensure correct torque retention and prevent loosening during operation. Cross-reference your transmission’s serial number with ZF’s compatibility charts to confirm fitment for non-standard configurations.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4646101072 | TRANSMISSION HOUSING | Encloses and supports all internal gear train components |
| 4646301201 | HOUSING | Secondary structural casing for clutch and valve body |
| 4646301166 | COVER | Seals the transmission and provides access for service |
| 0636101051 | CAP SCREW | High-tensile fastener for securing disc carrier assembly |
| 4646201018 | COVER SHEET | Protective shim between clutch pack and carrier |
| 4646301277 | SCREEN SHEET | Filter mesh for transmission fluid flow control |
| 4646201019 | COVER SHEET | Secondary shim for clutch pack alignment |
| 0730365125 | TYPE PLATE | Identification tag for transmission model and serial |
| 0631311009 | GROOVED STUD | Alignment pin for housing-to-carrier positioning |
| 0636010216 | HEXAGON SCREW | Standard bolt for auxiliary component mounting |
