That groove is unimportant, likely some result of the machining operation. It IS TROUBLING that even the Chinese can't get a shaft cut down to within 1/8" of the proper dimension
And if you think that's bad, I installed a Chinese Charley gas tank in my Dart. The hole for the fill pipe was off by over a half an inch!!. [Rock auto]. The fill pipe went in, but I had to slice up that rubber seal in the trunk to get the screws in.
