How do you check a tie rod end

Very simple with two people:

Have helper turn the steering wheel back and forth in arcs left/right. Have them start small and only increase as you need them to.

You will be looking from the front, underneath the coach. You will start at the steering box (forward of left front tire), working back to left steering knuckle, then right steering knuckle.

You are looking for any movement coming from the steering box end that causes play rather than exactly the same movement in that next component "downstream".

It is easiest if the helper's arcs are just enough to move the first component you are checking. That way, if the "downstream" component is not moving, you will quickly notice it.

On edit: no need to have engine running during the test.

jack the wheel up and shake wheel in and out look for play at tie rod end