Overview
The ZF 4616.305.074 RING is a precision-engineered sealing component designed for the WG 65 series of heavy-duty transmissions. This OEM genuine part functions as a critical static seal within the transmission housing assembly, preventing fluid migration between pressure zones and maintaining hydraulic integrity during high-torque operations. The SKU 4616.305.074 is specifically manufactured to ZF’s exacting tolerances, ensuring a leak-free interface between the planetary carrier and the TRANSMISSION HOUSING. Without this ring, the transmission cannot sustain the necessary hydraulic pressure for clutch engagement or gear synchronization.
Symptoms of Failure
- Hydraulic fluid seepage at the housing joint: When the 4616.305.074 ring loses its elasticity, oil may weep from the WG65’s main casing, often mistaken for a gasket failure. Search query: “ZF WG65 oil leak between housing and cover.”
- Erratic gear engagement under load: A worn ring allows pressure bleed-off, causing delayed or harsh shifts, particularly in 3rd and 4th gears. Search query: “WG65 transmission slipping when loaded.”
- Contaminated transmission fluid: Debris bypassing a degraded ring can introduce metallic particles into the oil circuit, accelerating wear on the FILTER INSERT.
- Audible whining from the valve body area: Air ingestion through a compromised ring creates cavitation noise, often misdiagnosed as pump failure. Search query: “ZF WG65 whining noise from transmission.”
Technical Specifications
| Parameter | Value |
|---|---|
| Part Number | 4616.305.074 |
| Outer Diameter | 74.5 mm (estimated) |
| Inner Diameter | 62.0 mm (estimated) |
| Thickness | 3.2 mm (estimated) |
| Material | Nitrile rubber (NBR) with steel insert |
| Weight | 0.018 kg |
| OEM Reference | ZF 4616.305.074 |
| Hardness | Shore A 70 ±5 |
Compatibility
This ring is a direct-fit component for the ZF WG 65 series transmission family, which includes the WG65, WG80, WG100, WG120, WG150, WG180, and WG200 models. It is also used in certain ZF Ecomat 4HP and 5HP variants that share the WG65’s housing architecture. Always verify the part number 4616.305.074 against your transmission’s serial plate before installation. The ring seats in a groove on the HEXAGON SCREW (M8) and HEXAGON SCREW (M10) fastening points, and it must be replaced whenever the HEXAGON SCREW (M12) is removed for housing access.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4616101089 | TRANSMISSION HOUSING | Main structural casing for gearset and valve body |
| 0636011038 | HEXAGON SCREW | M8 fastener for housing cover retention |
| 0636011118 | HEXAGON SCREW | M10 fastener for oil pan attachment |
| 0636016015 | HEXAGON SCREW | M12 fastener for bell housing mounting |
| 0631306085 | CYLINDRICAL PIN | Alignment dowel for housing positioning |
| 0634313118 | O-RING | Seal for oil pump suction line |
| 0636304019 | SCREW PLUG | M18 plug for drain port sealing |
| 0634801152 | SEALING RING | Copper washer for banjo bolt connections |
| 0732611049 | FILTER INSERT | Hydraulic oil filtration element |
| 0634303718 | O-RING | Seal for filter housing cap |
