16) The base of the wheel is already completed, lets move to the last 2 details. Select the exterior polygons of both sides:
17) Make sure that Use Pivot Point Center option is selected and than use Select and Uniform Scale tool to flatten those polygons a little. With Use Pivot Point Center option 3ds max will use as reference the center of the two selection group to flatten them separately.
18) Now change to Use Selection Center option and do the same thing, the polygons will be moved to the center of the object breaking the ball looking of the wheel.
19) To finish the model, lets make a little detail in the center of the wheel. Select the middle vertice in the center of both sides.
20) With Chamfer tool, create a new circular group of vertices.
21) Back to Polygon subobject, select the two new polygons created and use Extrude Tool with a negative value to create a hole.
22) Select all polygons and use Auto Smooth again to ajust the smoothing groups and it's done. Since this wheel will not be in prominence, we will not need to worry about it details to deep.