View
Navigate
Zoom
Selected (or the equivalent Navigation Bar command) to tightly enclose the crank within the display area. It does not matter if the crank is off-screen when it is selected.
Shape
Circle and
Select
Surfaces commands still active, draw a circle enclosing the hole where the arm and crank meet, as shown in the following image. 
CAD Additions
Joint and click OK to add the pin joint, which appears as shown in the following image. 