Be specific. How did you ‘add’ transparancy.
What do you want to achieve, what is the issue?
It would be good to see the original opaque shader as well so we can see what the issue is.
This article explains some of the problems you might face with alpha transparency.
When Alpha Blend transparency is used, the renderer has to decide the order that it will render the faces. This is easier in 2D since the vertices of each polygon will be the same distance from the camera, but in a complex 3D model like this it may guess incorrectly. I think Additive transparency avoids this issue.
You can try changing the blend type in your shader to one of these: Unity - Manual: Set the blending mode in a shader