Noticed tonight that I have a leak on my front axle. It is running down between the cast housing and the inner flange on the drivers side where the outer flange (that turns the cv shaft) bolts on. It looks like motor oil so it has to be gear lube. Is there a seal there that may have gone bad? Has anyone else had this? Any help is appricated. Gordon

 

This doesn't sound good. It seems as if something in the front axle is coming apart (like an axle bearing). Is your truck still under warranty? If so, don't waste any time getting it back to have this problem fixed.

 

No I am well out of warranty. I cleaned the gear oil residue off with a rag and drove 200 miles in 2wd and it is still dry. The level of fluid in the front pumpkin is perfect......1/8 in below the plug hole. Let me ask you this....and anyone else who is reading along feel free to chime in....when you wrap your hand around the big black end of the cv shaft just prior to it entering the differential (on either side) and you tug it inward and outward and un and down do you have any movement? In either 2 or 4wd? I do have some both ways, maybe 1/8-3/16 inward and outward and a bit less up and down. I only have 41000 on this truck and cant remember if im supposed to have this play or not. I cant imagine those being 100% snug simply for the pounding they take. I can drive like hell in 4wd up and down my gravel road in both hi and low with no noise or anything. Thanks for your help....Gordon

 

Hey toddyman88

Are your sure your frt diff is leaking? Do you do your own oil changes? I ask because I have seen many trucks that have oil in that area due to changing the oil filter. I have not seen many trucks with frt diff leaks, but it is very possible. Just wanted to cover all possible causes of the leak. Slight play in and out on the halfshaft is normal. Hope this helps.

Later

 

Xplorer.....Im relived to know that the play is normal. Yes I do all my own oil changes but the filter area looked clean for the most part. Maybe whenI changed the oil last the filter did not seat up good at first allowing some oil to seep around it dripping into this area, then sealed up with the heat. I know it was not wett there when i did the oil change beacuse for sure I would have noticed (pretty **** about all that stuff). Thanks for the imput and now that ive gotten it dry and clean Ill do another oil change and keep an eye on it. Gordon

 

There is a seal just inside the housing on both ends in the Chevy fronts that are known to be leakers. I would say there has to be a similar seal setup in these Fords.
Next time you notice it give it a sniff. The gear oil will have a sulphur smell to it and the motor oil will not. Also the gear oil leaks usually aren't as dark black as motor oil but that depends on what it runs over on it's way to where you finally see it.

 

Anybody figure out what this was? I have the same leak.

 

check the vent tubes on both the axles...this is the most overlooked (even by the dealer) cause of axle seals blowing out...no one ever checks these..i have seen people replace burnt out diffs multiple times without even checking the vent hose-the little vent cap gets broken off the tube fills with road grime/dirt/grease & when the diff heats up the gear oil has no where to expand so it will blow out an axle seal.

 

I don't know if this is what you have but my 97 Expy was blowing fluid all over the right front axle shaft, a-arms and all over the wheelwell. It turned out to be the vent for for the front axle housing. The vent tube was very short and the end layed just inside the wheelwell on top of the upper a-arm (barely visible). It hadn't leaked for over a year since I bought it but I think the line fell down onto the a-arm in the wheelwell and the air going by it created a vacuum and just pulled the fluid right out. I put an extension on it and ran it up into the engine compartment and it hasn't leaked again.

 

For those still experiencing this problem, here is what I had to do on my 2003 Expedition Eddie Bauer 4x4. My leak was exactly what you mentioned - about a teaspoon from the passenger side front axle where the flange is between the CV half shaft and the axle shaft coming from the differential.

Remove brake caliper and rotor. Remove anti lock brake sensor from knuckle. Remove dust cap and retaining nut from CV shaft. Remove steering knuckle. I tried to cheat by not removing the lower ball joint from the knuckle - just the upper ball joint & steering tie rod end. It is VERY difficult to get CV shaft out this way. It barely clears the knuckle. I just did not have a fork to separate lower ball joint. Remove 6 bolts on flange between CV shaft and axle shaft w/12mm 12pt socket. Remove CV half shaft. The axle shaft is held into the differential by a retaining clip/ circlip inside the differential. You can use a maul to beat the axle shaft out from the differential but the retaining clip will fall into the differential (requiring the removal of the diff cover). You may be able to reuse the clip if you can straighten it but its worth it to go to dealer for this low cost item as you do not want axle shaft to be loose in diff. While at dealer, you should also get the axle shaft seal. Mine cost $13 at dealer. I found out that Timken #3604 I got at parts store for $10 is not the right size. Remove 4 bolts from axle tube to diff and 1 bolt from axle tube to cross member. Remove axle tube from vehicle and use seal puller to remove bad seal. My seal would not come out with my seal puller. I had to chisel it out. The axle tube is very brittle and I chipped it a little. Replace seal, put axle shaft in tube, remount tube to diff and secure with retaining clip from inside diff. Replace everything else you removed to get to this point.

So after two full days of this adventure, I still have the same leak. Maybe even worse. I'm very disappointed and wish I'd not even bothered. The only thing I can think of that I did wrong was I should have lubed the rubber part of the seal with some wheel bearing grease before inserting the axle shaft. I also removed the vent tube form top of diff and blew compressed air through it to verify it was not clogged.