Oil Leak from Front Differential after 12 miles in 4WD at 70 MPH

When I got back on the highway I forgot to take my TRD out of 4WD. I then drove 12 miles at 70 MPH before switching to 2WD.

When I arrived home 500 miles later I found drops of oil from the front differential on the driveway. The left underside of the truck was damp with oil so I had a real good look underneath but was not able to find the source. No oil around the drain and fill plugs and as near as I could make out the leak originates somewhere near the top of the diff case. I stuck my finger into the fill hole and there is still plenty of oil in the differential.

I cleaned off the splatters (there were none on the right underside) I left the rear rock shield off and will check it in a few weeks. There was no oil at the left and right jack shaft outputs. Could the oil have been thrown out the breather during the 12 mile run?

 

Blow by tube maybe?

 

At least on my 2003, the breathers are easy to check from the engine bay. Most likely the culprit but sometimes hard to tell for sure.

 

Fresh oil change (diffs and trans) in September. The oil that's dripping is heavy, clean, and smells like 90w.

I'll take a look from the engine bay and see what I can see.

Thanks for your replies.

 

Took a look, cannot see the top of the front differential in my TRD. Also took a 6-mile drive on the highway, no sign of a leak when I returned.