Oil leak Silverado

[chev2865]

Hello, I am new here to the site and have a oil leak that I am not sure where it is coming from. I have a 2001 Chevrolet 2500HD. The leak seems to be dipping off the starter bolts and the starter is covered in engine oil. There is also oil all over the bell housing as well. This is what makes it tricky to diagnose. At first I thought it was the rear main seal but after I saw it dripping from the starter I thought it must be something else. What could it be that is leaking on or above the starter? Any ideas or comments are greatly appreciated. Thank you!

[txab]

Check the crankshaft position sensor, it's above the starter. Also inspect oil pressure sending unit

[chev2865]

Check the crankshaft position sensor, it's above the starter. Also inspect oil pressure sending unit

thank you. Does the whole crankshaft position sensor have to be replaced or just the o-rings?