Oil Seal - Inner Axle Housing

The Oil Seal - Inner Axle Housing (Moser Engineering part number 7S151) is a critical wear item designed to prevent lubricant leakage and contamination at the inner axle hub interface. Whether you're running a street machine, weekend track car, or performing a complete rear-end rebuild, this seal is engineered to maintain gear oil retention in high-performance and stock applications alike. Built by Moser Engineering—a trusted name in performance axle components—this seal addresses one of the most common failure points in differential assemblies.

This inner axle housing seal features a 2.5-inch outer diameter (OD) and 1.531-inch inner diameter (ID), with a dual-component construction of rubber and steel that combines flexibility with structural integrity. The lip-style design creates a dynamic barrier against gear oil egress while accommodating shaft runout and thermal expansion. Rubber compound and steel backing work in tandem to withstand the centrifugal forces, temperature cycling, and mechanical stress inherent in differential operation, making it far superior to inferior aftermarket alternatives that degrade rapidly under sustained load.

This seal is essential for anyone rebuilding or upgrading an axle housing, replacing failed original equipment seals, or transitioning to a higher-performance rear-end configuration. Installation involves pressing the seal into the inner axle housing bore—a straightforward procedure for technicians familiar with axle work. Proper installation, combined with quality gear oil and correct differential setup, ensures years of reliable service without the mess and performance loss associated with leaking differentials. Measure your existing seal or consult Moser Engineering compatibility guides to confirm fitment before ordering.