Fishnaked

Last Sat, I had my 95 F150 5.8L auto parked on a slight incline, drivers side down. Sun morning, I noticed what smelled like gear or hydraulic fluid. I crawled underneath and found oil leaking out of tube originating from the rear end, drivers side....routed upwards, ending on the frame. It's an open tube....so I assume it's a vent of some kind.

I'm sure it wasn't leaking when I parked it as I have a keen nose...and I pitched my tent just feet away. I have never noticed it leaking before, and now that I'm on flat ground, it's currently not leaking.

Sat, before parking on the incline, I had it in four low, creeping up a rough, dirt mountain road with a trailer full of lumber.

I thought rear end oil was thick. This oil appeared thinner and didn't smell like regular oil.

Any ideas? Should I be concerned?

Snaggletooth

I know that's a vent for the rear diff but I'm not sure what fluid should be in there.

Fishnaked

Thanks. I wonder why fluid was leaking out of mine though? Surely someone knows.

sdmartin65

The rear end might be a bit over full or the vent is shorter than required because the upper portion broke off. With truck cool on level ground remove the check plug and let excess fluid drain out. The vent tube should run up into the frame area and have a check valve on the end.
Hope this helps.

Fishnaked

Thanks! I'll have to look again but I don't recall seeing anything but an open tube. Don't recall a check valve. The tube is definitely mounted securely to the frame and faces up. For what it's worth, the truck only has 63k on it and is in excellent condition.

Also, should proper oil for the rear end smell different than regular motor oil? As mentioned before, this fluid had a different smell to it. I wouldn't have noticed the drip otherwise. Reminded me of how hydraulic fluid smalls.

sdmartin65

The rear differential has gear oil in it and will have a nasty smell, especially if it is well used.