??????

 

Gasket leaking,vent tube blocked,pinion seal leak.

 

Any recommendations? What should I do?

 

Your picture doesn't show the front of the differential housing. Is it wet behind the yoke at the pinion seal? Even so with the vehicle on level ground remove that rubber plug and check the fluid level. It should be even with the bottom of the hole or may dribble out a bit. Next clean away all that dirt and grease and check that the vent tube and breather at the end of it are clear. Then drive it and see if that resolves the issue. Won't hurt to drive it.

 

Obviously that cover's been off before. Notice the lack of part number and ratio tags. It may be just the cover is leaking. The oil around the plug may just be from checking the level. The main thing is the pinion seal may be leaking. If it's not using much lube, just keep an eye on it. Changing a pinion seal is a complicated procedure to do it right.

 

Good eye!

From what I can make of his pic it doesn't look like the pinion seal is the issue. C8.25's have the crusher sleeve. Correct?

 

Yup.

 

Where is the vent tube end breather?

 

It'll be a rubber hose connected to the top of the axle tube. Follow it to the end and you find the breather valve.

 

It should be attached to the frame rail at the top of the fuel tank or there abouts.