What are these hoses - oil leak

Anyone know what these hoses are? They seem to be leaking enough to drip down to my bump stops. The engine and surrounding area is clean, no leaks. Leak appears to come from these two hoses. What are they?

 

Transfer case and front differential breathers (vents)

When was the last time you had the front diff fluid changed?
Over filling the differential will cause it to leak from the vent.
As will running a heavier fluid in some cases.

Are you sure they are both leaking, or just one?

 

How does one overfill a differential?

I've seen this before and haven't really understood what causes it.

Too much heat?

 

About 500 miles ago I changed both the front diff and transfer case fluid. Transfer case fluid was genuine Toyota. Front diff was Amsoil Severe Gear 75w140 - I am re-geared w/ Nitro 5.29.

Hard to tell if both are leaking. I am not sure which one but based on what you said, most likely the front diff given the heaver diff oil that I used. It can't be an overfill. I was on level ground and let the oil flow over the fill hole, until no more flow - and I waited.

 

If you jack up one side (left/right), fluid will run down the axle tube. For instance the passenger side is on the ground, driver side jacked up. When you let the truck down “level” fluid runs back into the differential housing, over filling it.

And a lucky few of us had them leak when going with heavier weight fluid.

 

Mine leaked when I went with the heavy fluid.
I even made a thread on it.

https://www.tacomaworld.com/threads/front-diff-leaking-gear-oil-from-the-breather.744067/

 

clean well and monitor

 

I guess I am one of them lucky ones. Old oil was 75w90 but I was worried about the 5.29 gears (and heat).

I jacked up the truck, and even used a level to make sure the truck was level (front-to-back, left-to-right).

No harm though when it vents?

 

Yup, did so, drove the truck about 20 miles today - no new leak on the caps.

 

If I knew what those hoses were I could have searched for your thread. Thanks for the tip!