Rear differential oil leak

[CliffC]

Have a 1999 Explorer, was my daughters car that I now use occasionally. Just noticed a hose hanging down under the rear axle/differential, I'm sure it's supposed to be connected to something since it has a clamp of some sort on the loose end. Crawled under and see some evidence of fluid on the axle but no drips on the driveway but couldn't see where it's supposed to be attached. Any suggestions would be appreciated. If necessary I can take a pic and add.

 

[koda2000]

That's the differential vent tube. Under normal circumstances it doesn't usually cause leaking if it comes off. There's a nipple on one of the axle tubes (driver's side I think). It's located on the top of the axle tube, that's where the hose needs to go. The other end is clipped to the frame. W/out the hose you will get water into the diff and that will ruin it. On some Fords the nipple for the hose is the bolt that holds the rear hydraulic brake line junction on the axle tube.

I would put on a new hose as the old one is no doubt dry rotted and cracked. As you don't how long the hose has been off, it might be a good time to service your rear diff and check your axle seals while your at it.

Edit:
I just looked at our 2000 Mountaineer's rear axle. The nipple was on the driver's side, close to the brake backing plate, and was not part of the brake line junction.

 

[donalds]

Make sure that tube is clear
Mine leaks just a ill bit around that nipple
Remove the nipple and hose at the same time use a 1/2 inch open end wrench
Blow through the hose and nipple with brake clean put some Teflon tape on the nipple and reinstall be very careful not to strip the 2 threads that are in the axle tube

 

[Mbrooks420]

Is the axle wet where the driveshaft connects? Very common place for them to leak, and they won’t leak unless the axle is turning so it’ll fling off, or get blown away by the air flowing under the truck.

 

[CDW6212R]

Ditto. It's time to service the rear(R&R the cover and refill), and you should be able to get away with cutting an inch of that old hose off where the clamp is. Check for metal debris in the old gear oil, if it's not really clean, it'd be smart to also replace the axle bearings.

 

[CliffC]

Thanks for all your help.
Actually joined some time ago but hadnt asked before.

 

[CDW6212R]

Here's a picture of that rear vent hose and where it attaches;

 

[CliffC]

Thanks for the photo.