I have a 2015 3500 ccsb with a 68re with 14700 and noticed that my rear main seal looks like it's leaking. My truck was made last February. My brother has almost the same truck and his was leaking too. Anyone else have this problem?

 

Do you mean engine or transmission? If transmission on one truck I had a transmission seal leaking soon after new that got worse quickly, I picked up the seal but after pulling the drive shaft I noticed a scratch on the part that goes into the transmission as though the shafts are stored on a metal rack and dragged off for installation, I polished the scratch with a fine stone and installed the new seal, it was still good when I sold the truck. If engine... that's what warranty is for.

 

Rear main on engine

 

Any chance it might be assembly lube instead??? It's actually kind of rare to have a rear main seal leak on these newer trucks at such a low mileage.