QC Pinion Seal 3/4

The QC Pinion Seal 3/4 by ALLSTAR PERFORMANCE is a critical wear component designed to prevent gear oil leakage at the pinion shaft entrance of 3/4-inch differential housings. This seal sits where the driveshaft interfaces with the differential, enduring constant rotational stress and exposure to hot differential fluid. Whether you're rebuilding a rear end after high-mileage wear, upgrading a performance differential, or restoring a classic truck, replacing a degraded pinion seal is essential maintenance that prevents costly oil loss and differential damage.

This 3/4-inch pinion seal features a precision-engineered elastomer lip designed to ride against the pinion shaft while accommodating rotational speeds without excessive friction. The seal's compact 4 x 0.9-inch profile allows straightforward installation into the differential housing without requiring complete drivetrain teardown. ALLSTAR PERFORMANCE's manufacturing ensures consistent diameter tolerances and material durability, resisting thermal cycling from -20°F to +220°F differential operating conditions. The lightweight design (0.16 lbs) reflects efficient engineering—form follows function without unnecessary material.

Hot rodders, truck enthusiasts, and transmission shops install the QC Pinion Seal 3/4 during differential rebuilds, when converting to locking differentials, or after notching a housing for custom driveshaft clearance. Symptoms of a failing pinion seal include visible oil weeping around the driveshaft yoke, a slow differential fluid drip on your driveway, or metallic shavings in the oil during a service interval—all signals that this component is due for replacement. Verify your differential housing diameter (3/4-inch) before ordering; compatibility is critical for a watertight seal. Installation typically requires the driveshaft removal and minor housing prep, making this an accessible upgrade for experienced DIY builders or a quick service for professional shops.