Overview
The ZF 0634.305.075 RECTANGULAR RING is a precision-engineered sealing component specifically designed for the WG 65 Series transmission. This OEM genuine part sits between the 4616105415: OUTPUT shaft assembly and the TRANSMISSION HOUSING, creating a critical static seal that prevents pressurized oil from escaping the clutch pack area. As a rectangular cross-section ring, it provides superior sealing surface contact compared to standard O-rings, ensuring consistent hydraulic pressure within the transmission’s valve body circuit. The SKU 0634.305.075 is the direct factory replacement for this application, manufactured to ZF’s original material and dimensional specifications.
Symptoms of Failure
- External oil seepage at the output flange interface: When the rectangular ring hardens or cracks, you will notice fluid weeping around the OUTPUT FLANGE mating surface, often mistaken for a flange gasket leak.
- Delayed engagement or clutch slip under load: A worn 0634.305.075 ring allows internal cross-leakage, reducing line pressure and causing the transmission to hesitate when shifting from neutral to drive.
- Low transmission fluid level without visible external drips: The ring failure can cause internal oil migration into the bell housing, leading to gradual fluid loss that is only detected during service intervals.
- Erratic shift quality in higher gears: As the seal degrades, hydraulic pressure fluctuations become more pronounced, particularly in the WG65’s 4th and 5th gear circuits.
Technical Specifications
| Parameter | Value |
|---|---|
| Part Number | 0634.305.075 |
| Cross-Section Shape | Rectangular (square profile) |
| Inner Diameter (approx.) | 75 mm |
| Outer Diameter (approx.) | 85 mm |
| Cross-Section Width | 3.5 mm |
| Material | Nitrile rubber (NBR) with PTFE coating |
| Hardness | Shore A 90 ±5 |
| Weight | 12 grams |
| OEM Reference | ZF 0634.305.075 |
| Temperature Range | -40°C to +120°C |
Compatibility
This rectangular ring is primarily used in the ZF WG 65 Series, including the WG65, WG80, and WG100 models. It also fits select WG120 and WG150 variants that share the same output shaft seal groove dimensions. The part is not interchangeable with the WG180 or WG200 series, which use a larger diameter ring. Always verify the groove diameter in your TRANSMISSION HOUSING before installation. For secure mounting, pair this ring with the HEXAGON SCREW (0636011038) to ensure proper compression of the sealing surface.
Related Components
| Part Number | Name | Function |
|---|---|---|
| 4616105415 | OUTPUT | Transfers torque from planetary gearset to output flange |
| 4616303144 | OUTPUT FLANGE | Connects transmission to driveshaft |
| 4616101094 | TRANSMISSION HOUSING | Main structural case containing all rotating components |
| 0636011038 | HEXAGON SCREW | Secures output flange to shaft |
| 0636011118 | HEXAGON SCREW | Mounts housing cover plate |
| 0636016015 | HEXAGON SCREW | Fastens valve body assembly |
| 0631306085 | CYLINDRICAL PIN | Aligns housing halves during assembly |
| 0634313118 | O-RING | Seals oil pump suction line |
| 0732611049 | FILTER INSERT | Traps debris in hydraulic circuit |
| 0634303718 | O-RING | Seals cooler line connection |
