Loctite RTV Black High-Performance Silicone Part No: 2638166

The 2638166 RTV Black High-Performance (Loctite 598) is a premium silicone gasket maker formulated for rugged sealing challenges in heavy-d­uty truck applications. As a room-temperature-vulcanizing (RTV) oxime silicone, it cures upon contact with moisture to form a flexible, high-strength gasket that resists motor and transmission oils. With an operating temperature range from approximately –54 °C to +260 °C, it maintains flexibility under extreme thermal stress. The thixotropic paste stays in place during application, prevents sagging, and fills flange irregularities.Typical use cases include oil pans, transmission housings, valve covers, timing gear covers, and differential covers. The cured gasket resists aging, vibration, and thermal cycling without hardening, shrinking, or cracking — ensuring long-term sealing performance.