Reference for Mouse Wheel

Mouse Wheel and Middle Button Navigation

To Do this...
Zoom in scroll the wheel button forward.
Zoom out scroll the mouse wheel backward.
Pan hold down the middle mouse button, and then move the mouse to pan.
Orbit press and hold SHIFT and hold down the middle mouse button, and then move the mouse to orbit about the currently defined pivot point. This function is not available in a 2D workspace.
Change the pivot point press and hold the SHIFT and CTRL keys and hold down the middle mouse button, then drag to the point on the model you want to use as the pivot point. This function is not available in a 2D workspace.
Note: The above does not apply when using legacy navigation modes, all of which have their own wheel/middle button behaviors. In a 2D workspace you can only pan and zoom. Also, the Shift+ Middle Button function is only available in a 3D workspace.
  Wheel Middle Button SHIFT + Middle Button
Non-Navigational Tools
Select Zoom In/Out Pan Orbit
Measure Zoom In/Out Pan Orbit
Markup Zoom In/Out Pan Orbit
Legacy Navigation Modes
Walk Look Up/Down Glide Camera Glide Camera (Faster)
Orbit Zoom (Roll) Glide Camera -
Examine Zoom (Roll) Pan -
Turntable Tilt Up/Down Pan -
Standard Navigation Modes
Pan Zoom In/Out Pan Orbit
Zoom Window Zoom In/Out Pan Orbit
Zoom Zoom In/Out Pan Orbit
Orbit Zoom In/Out Pan Orbit
Free Orbit Zoom In/Out Pan Orbit
Constrained Orbit Zoom In/Out Pan Orbit
Look At Zoom In/Out Pan Orbit
SteeringWheels Zoom In/Out Pan Orbit