Oily breather tubes? Front and center differential?

[freeflight]

04 V6 4runner. Found a pair of oily breather tubes on driver side, next to engine oil filter housing. Dripped Oil stained LCA. They seem to root to front and center differential, but I am not too sure. Is this caused by overfill of differential oil?

Just had front diff oil drain and filled when CV axle was replaced. The mechanic probably put over 1.5qt in it. I did the center diff oil change, put in less than 1.4 qt when it overflows.

 

[freeflight]

There are two breather tubes. The breather on thick tube rotates free, don't have much oil. The breather on the thin tube seems stuck, barely moves. That's where the gear oil is from. The thinner tube is in the back.

It turns out the stuck breather is for center differential.
Part number:
Front diff breather 90930-03136
Center diff breather 90930-03172/90930-A3005
Rear breather: 90930-A3001

TRANSFER CASE & EXTENSION HOUSING. 2004 Toyota 4Runner | Toyota

 

[freeflight]

Although the factory diagram shows smaller breather is for the center diff, the thin line traced to a box (ADD 75W-90) next to front diff.

Front diff oil level is good now, a couple of mm below the fill hole. Didn't have to drain it.

Is stuck breather the cause for gear oil leak?

 

[freeflight]

Replaced both breathers and cleaned oil residue. Drove in 4WD for 10 miles, didn't see new oil seeping out. Call it good for now.