Modulator Plug Gasket - Pack of 5

Package Quantity: 5

The Sonnax 3543L‑5 Modulator Plug Gasket is a precision-engineered seal designed specifically for GM Powerglide transmissions. Sold in convenient five‑piece kits, this replacement gasket provides a reliable seal between the transmission case and the modulator plug (part number 28738-01K), preventing fluid leakage and ensuring consistent line pressure. Manufactured to Sonnax’s exacting standards, the 3543L‑5 gasket restores the vacuum sealing performance of the original OE component and supports both stock rebuilds and high-performance Powerglide setups.

Whether used during routine maintenance or in dedicated race builds, this durable seal contributes to improved transmission health, reliable modulation, and confident driving performance.