I do not know if it helps you but I have seen that happens when the retainer or seal used is not the right one can be well but inside the seal it brings some lines that are called stark and on the surface where it has the numbers it brings an arrow this indicates the direction of rotation of the piece in which the seal is mounted if the arrow indicates the turn unlike the turn of the crankshaft. A friend with the seal of a Honda was given the seal of another engine and the turn was different. The other may be that someone aya damaged the crankshaft track and you have not noticed when riding it, check it careful mind and make sure that when mounting the new seal is adjusted to the center.