My box is similar, on downchange from 3rd to 2nd its notchy. Its not grinding. I was worried but Powervehicles said it was fine, ive changed the oil for redline box oil and it was the same. If i heel toe its not notchy at all, and its fine everywhere else. It actually feels like downchanging a dog box, almost exactly the same to be honest

Someone else told me they had an r154 rebuilt and was still notchy.

Im no expert but if its notchy, not grinding i wouldnt worry unless its getting worse