Crank seal leaks are a common problem, so replacing the seal is the only solution.
Type 1, type 3 and CT/CZ engines are only equipped with a crank seal behind the flywheel. On the pulley side, they are sealed by grooves in the pulley that push the engine oil into the crankcase. If the engine leaks at this location, these grooves may be worn, but it is more common for the engine crankcase to be worn at this location. The only solution is to mount a Sand Seal type pulley (if available for your engine type, it will be listed in the related parts tab).
Type 4, WBX and Diesel engines are equipped with a seal on both sides, i. e. behind the flywheel and pulley.
It is very important that the seal is pushed evenly and exactly directly into the crankshaft housing. If this is not the case, the leak will not disappear. The use of positioning tools to correctly mount the seal is therefore not an unnecessary luxury. If a tool is available for your engine type, we recommend that you order it (see related parts tab).
For some seals, you have the choice between two versions: the standard seal (which is the same model as the original) and a version with an additional dust lip. The additional lip prevents dust and dirt from accessing the seal itself. If dust and dirt enter the contact surface, the seal will no longer stop it, causing a leak.
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 seal will not be able to seal it in the long run, resulting in a leak.
Note : The additional dust lip also has a disadvantage compared to the standard model; the contact surface must not be damaged. It often happens that the contact surface of the flywheel is not finished cleanly (especially for after-market flywheels), the additional dust lip must do its job on this surface. If the surface is not smooth, the additional dust lip will rotate and may tear 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 experience with all brands of after-market flywheels, we recommend using this seal only with an original Volkswagen flywheel.
In addition to the standard crank seal with and without additional dust lip, for some engines you also have the choice of a silicone version with or without additional dust lip. These types are generally more watertight (if available for your engine mentioned on the alternative tabs).
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