Here is a shot of the thrust bearing under the cam hold down.
Below are pics of the reluctor for the Cam position sensor; someone can fill in more detail but the basics are that the position sensor is magnetic, and the slot disrupts the signal and this is what tells the engine the position and RPM of the cam.
Below is a shot of the front of the cam, as you can see the gear is pinned at the top, there are plate before and after the gear when the pin is put in place it locks in the position of the gear.
