front Diff question

[aknight_sa]

Guys, this might be a noob question. there is a hose connected to my front Diff which i dont understand the reason for. it goes from the diff housing to the steering pump.

anyone tell me what is this for?

 

[K85 Octane]

vent
it goes up near the top of the core support

 

[Bent77]

Guys, this might be a noob question. there is a hose connected to my front Diff which i dont understand the reason for. it goes from the diff housing to the steering pump.

anyone tell me what is this for?

It actually terminates on the frame up above the axle. It’s a vent for the diff. Should have a white or yellow dohongus

 

[rampage]

The diff creates heat which is absorbed by the fluid. As fluid heats it expands and the air needs some place to go, which is out the breather tube. If the diff was a sealed unit, the pressure built up from the expanding fluid would blow by the seals where the axle shafts enter the diff housing creating a mess and loss of fluid.

 

[aknight_sa]

Thanks Guys!

 

[diesel4me]

That hose also allows water to flood the diff if you drive thru a deep enough puddle too...so a fluid change isn't a bad idea if the truck has been in deep water...the plastic dewhicky in the upper end of the hose supposedly prevents water from getting in,but will let pressure out,but they don't always work after a few decades..