Just noticed this today and dont know if it is a big deal, but theres a discoloration on and around the drain plug on the front differential. I looks like oil but when i touched it i didnt get any oil on my hands. Is my differential leaking?

 

The plug is above the diff oil level, so it's probably not leaking. Make sure it's tight. Try and loosen it first, before you torque on it.

It could be something you picked up while driving, or it could be dripping from somewhere else. Check the steering box to make sure it's not leaking. Look from the bottom to see if there is any oil coming from the front of the motor. There is an accessory plug next to the CP3 injection pump that I had replaced on my 06. I also had to adjust the steering box shaft once. It was leaking some power steering fluid. While you are there, check the injection pump to see if it is leaking any fuel.

It's probably nothing, but it's worth checking things above that may have dripped down.

 

I would check the tightness of the drain plug. If its not running to the bottom of the differential, I wouldn't worry about it.
Synthetic fluids can seep and find ways to leak real easy.