You could use the See Thru function but this will not "fly" trough the assembly it will only allow you to see all components/parts hidden by other objects.
Or if you push CTRL+H it will open up the section view menu, with a lot of options to play with.
And now, in navigation mode, the fun starts trying to master the controls
Ctrl+Shift+MB1 (drag upwards ="increase perspective") - You need perspective to be able to fly past objects.
MB1 (slow) left/ right = turn left/right
MB1 up/down = fly in/out
Shift+MB1 = up/down = Fly-turn up/down
Shift+MB1 = right/left = roll (rotate about screen z)
Ctrl+MB1 up/down/right/left = ("pan") fly sideways
Under View Navigate Options you can set the sensitivity, the flight might be too high speed per default.