ZF 0730.062.978 RING for WG251 | OEM Genuine Part

Overview

The ZF 0730.062.978 RING is a precision-engineered sealing and positioning component designed specifically for the WG251 heavy-duty transmission series. This OEM genuine part sits between the transmission housing and the clutch assembly, functioning as a critical interface that maintains hydraulic pressure and prevents contamination ingress. The SKU 0730.062.978 is manufactured to ZF’s exacting tolerances, ensuring a secure fit that supports the TRANSMISSION HOUSING and adjacent HOUSING components during high-torque operations. Without this ring, the transmission’s internal oil circuits would lose integrity, leading to performance degradation.

Symptoms of Failure

• Oil leaks around the transmission housing interface: A worn 0730.062.978 ring allows hydraulic fluid to escape, often visible as drips near the COVER joint. This is a common long-tail search query for “ZF WG251 oil leak repair.”
• Gear slipping under load: When the ring loses its sealing ability, pressure drops in the clutch pack, causing erratic shifting or delayed engagement—frequently searched as “WG251 transmission slipping symptoms.”
• Contaminated transmission fluid: A failed ring permits debris to bypass the filter, leading to gritty oil and accelerated wear on internal parts. Technicians often search for “ZF transmission debris contamination causes.”
• Increased operating noise: Loss of hydraulic damping from a degraded ring results in metallic clattering during gear changes, a symptom tied to “WG251 noisy transmission fix.”

Technical Specifications

Compatibility

This ring is engineered for the ZF WG251 transmission series, but it also fits select models in the WG180, WG200, and WG250 families due to shared housing dimensions. It is a direct replacement for the sealing ring in the clutch drum assembly of these gearboxes. Always verify fitment with your specific transmission serial number, as variations exist in early and late production units. The ring works in conjunction with the CAP SCREW that secures the cover plate, ensuring no oil bypass occurs at the fastening points.

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