Have a new to me 2012 Sierra 4WD SLT Duramax with 108k miles.
Used car lot was nice enough to power wash the underside to hide the oil leak. Well, now that it's mine (purchased from Houston, TX), it's leaking.
I've read that there's multiple locations for these to leak, but fortunately, the rear main seal is very rare. More common locations seem to be the oil pressure sensor, the lower oil pan gasket, and the oil galley plugs on either side of the crank.
After crawling under it, about 1/2 way down the passenger side, the oil pan goes from bone dry to soaking wet at one of the oil pan bolts. Based on this, I'm ass-u-me'ing that the lower oil pan gasket is leaking at this point, since the block above it and everything in front of it appears to be dry.
I watched a video on replacing said gasket, and it appears pretty straightforward. Pull out 4 bolts and pry out the engine cross member, then drop the pan, clean the surfaces, and replace the parts.
I simply do not have the time or gumption to do said repair. If someone on here is interested in doing a quality repair for less than 'stealership' pricing, I can pay in cash or rifle/pistol brass, your choice.
*ETA* St. Louis metro.