Well now Im leaking fluid with my rear diff. But Im leaking at the yoke. What or how the hell could I have messed up the seal at the yoke. Not leaking really bad but when i drive it mists fluid all under my truck. The only thing I can think of is me backing over some baby oine trees. But could that have done it??

 

its your pinion seal. chances are you didnt make it leak. the seal just wears out usually. check and make sure the diff vent tube isnt plugged allowing presure to build in the diff.

 

where would i find it

 

vent tube located top of axle tube.

pinion seal is behind the companion flange (the ring the driveline bolts to)

 

WTF is a "oine" tree?
If it were mine leaking i'de take it to the dealer or a differential "only" shop to have it repaired!

 

If it were mine leaking i'de take it to the dealer or a differential "only" shop to have it repaired! [/QUOTE]

Right. I learned that lesson the hard way.

 

sorry for the typo, I meant pine tree. Well its not leaking bad at all. I drove it for about a week, about 2 tanks of gas, and it only lost about 2-3 oz's of oil. But not there is a either a grinding or a vibration sounds when I hit the gas but only when I touch the gas. Its gets louder as I go faster and then stops when I let off the gas. I have no idea what it is, but its coming from the rear. Its just started a few days ago. Any ideas???

 

sounds like the Pinion bearings going bad. they've either worn out or become loose, allowing that grinding driveline noise+ fluid slingin. go get it checked out before you get stuck somewhere.

 

Yep,you've got a problem now! Try to find a "differential" only shop first before going to Ford!

 

Yeah.

Get it fixed.

 

is that a limited slip? just curious
better have it fixed before it starts tearing things up, any measurable amount of diff fluid leaking inside a two week period is TOO MUCH and unacceptable in my book.

sounds like the same thing that happened to my chevy, reason I got rid of it. I am pretty sure the same thing is eventually going to happen to this Ford. These long cab trucks, have a lot of weight in the center of the frame. I think it makes the yokes move around more than they should..or were designed to.
Both of these trucks do the same thing, when you come to a stop, it kind of rocks to and fro. I can picture the driveshaft working in and out. The crush sleeve, the pinion bearing, and seal .. then the pinion itself starts to work in and out on the ring.

 

Doesnt a gear install kit come with a pinion bearing? Im planning on having gears put in in Feb. I dont drive the truck really that much at all. Probably about 100 miles or less per week. Just for knowledge wise, what could happen if it I kept driving it. Im not going to but you had said I could get stuck somewhere. What would it explode??

 

Posi unit?

if you keep driving it with a bad pinion bearing, that means the pinion "shank" is walking anyway it wants inside its housing, which means it could start clipping ring gear teeth.. for starters.

 

no posi unit. The bearing hasnt exploded or anything. It just sounds like its grinding a little. And even if it start chipping, Im getting gears in Feb anyway. I think it will last that long. I dont drive it that much anyway. And besides, if for some reason chips all the teeth off the ring gear and wont move, I have 4WD so Im not completely stranded anyway. I just wont drive it at all if I get to that point but I dont see that happening between now and mid Feb.

 

A bad pinion bearing will make a whining noise at all speeds. It will also degrade the pinion seal. If it is making noise and slinging diff fluid everywhere, I would get ti fixed right away.
Even with new gears in Feb. you will need to change out all of your bearings even at the wheel ends if there is metal flying around in the fluid.

Why wait till Feb to get your new gears in?

Just curious, what gears are you going with?

Also you mentioned the oine (pine) trees. Did you check your driveshaft for damage? Any dents or dings will take it out of ballance and cause vibrations.

Good luck.