I have a 2005 Ram 1500 Quad Cab 4WD and noticed a leak at the back end of the drive shaft today. Just a little bit of fresh oil dripping off of the drive shaft itself.

Photo attached, any thoughts on what this is and what it'll take to fix it?

 

Pop the cover on your diff you'll probably find it full of metallic fluid from clutch pack retainer failure . This metal contaminated fluid destroys bearings ,races ,eventually seals , due to compromised tolerances . Good luck. Hope I'm wrong . Fix is total overhaul or replacement .

 

Pinion seal. Pretty common. Buy a good quality seal. Remove drive shaft. Remove yoke nut. Easier with air. I would change diff fluid while your at it

 

Your driveshaft balance fluid is leaking out. Soon you'll notice a vibration that will only get worse.
Contact a garage immediately. Make certain you pay extra for quality fluid. Cheap stuff freezes in winter.

 

I appreciate the quick feedback and direction. I'll get to a garage for an estimate early this week!