D90 body lens mount
The 7 o' clock position? That's the AF drive. It's supposed to protrude since it mechanically couples to AF lenses. It's also normal for it to wiggle about.
Anyway, try checking for loose screws or bent leaf springs on the inner side of the mount. There should be three, one under each protruding tab of the mount.
|Nowhere by Nanard 92|
from The Illusion of Depth and Distance
|Green Tomato by lim yau tong|
from Growing Fruit