Wholesale Closeout BlueDevil Transmission Sealer Transmission Sealer; Permanent Repair; 16 Ounce. BlueDevil Transmission Sealer permanently seals fluid leaks in your transmission, guaranteed. It restores gaskets and seals transmission leaks fast. Guaranteed Permanent Seal Restores Dried, Cracked, and Shrunken Rubber Seals Works in Manual or Automatic Transmissions