Type2 Split Bay T25 Silicone crank seal with dust lip type1 engines
A standard crank seal with rubber as the main component dries out after a while, there is nothing else to do but replace it if it leaks. A crank seal whose main ingredient is silicone does not experience this phenomenon and therefore has a very long shelf life. Silicone is smoother and softer than rubber, which makes it easier to mount the crank seal and makes it more waterproof against the flywheel. There is also a disadvantage, because of the ease of assembly, you are quickly inclined to assemble it without accessories. Don't do that! Silicone is more vulnerable than rubber, so always use the right tools.
For type 1, type 3 and CT/CZ engines, two versions are available: the standard crank seal (which is the same model as the original) and a version with an additional lip.
Extra dust lip
If the crank seal of your choice is equipped with an additional dust lip, this extra dust lip prevents dust and dirt from accessing the seal itself. If dust and dirt get onto the contact surface, the crank seal will not be able to stop it in the long term, resulting in a leakage. A double lip silicone seal is unique and is one of the best crankshaft seals available.
Caution : The additional dust lip also has a disadvantage compared to the standard model; the contact surface must not be damaged down to the flywheel. It often happens that the contact surface to the flywheel is not cleanly finished (especially for after-market flywheels), the additional dust lip has to do its job there, if it is not a smooth surface, then the additional lip breaks and can damage the sealing lip. Before starting to use the double lip seal, it is important to carefully check the flywheel and remove any irregularities from the flywheel (polishing). Due to the experience gained with all makes of aftermarket flywheels, we recommend using this retaining ring only with an original Volkswagen flywheel.
