Applying for tenure track position in mechanical engineering with lack of relevant coursework experience?
This is not necessarily a big problem, or an unusual one. Not every professor in a department is expected to be able to teach every course. I trained as a physicist, but I'm now in a nuclear engineering department.
As part of your application, you may be asked to write a teaching statement. In this, you should identify i) a few existing courses within the department which you can teach and ii) some brief ideas for new courses you could teach. These new courses could easily be tailored to your expertise. It is also entirely possible to learn new material and to teach it.