Drivers side half shaft seal

[Trent_Au]

hi, I am having issues with my 2008 expedition, the drivers side half shaft seal (where the cv shaft goes into the front diff) is leaking. I've had the seal replaced twice but still after a long highway drive either the seal fails altogether or there is a leak of oil down the diff case. What can cause this seal to continually fail? I've had 2 different mechanics replace the seal yet it's still leaking. I've taken it to another mechanic but they can't look at it until tommorow, I've asked them to check the breather to ensure it's not blocked. Does anyone have any other suggestions that could help me?

It doesn't leak straight away it takes awhile, usually after I have done 100mi or so.

 

[99WhiteC5Coupe]

I would suspect that the differential case vent (breather) is clogged or blocked. Some are mounted on top of the case, others are mounted at the end of a vent hose (which is attached to the case). If you have a vent hose type, ensure the hose is not cracked, kinked or pinched.

After driving for 100 miles, enough pressure has built-up to force oil out of the seal, or out of the vent and down the side of the differential.

I would replace the vent / breather with a new Ford part.

 

[Trent_Au]

That's hopefully what the mechanic tomorrow will do, if the vent is the issue and they replace it should I get them to replace the seal again also? If it's leaking oil now will it stop once the diff can breathe?

 

[99WhiteC5Coupe]

I

That's hopefully what the mechanic tomorrow will do, if the vent is the issue and they replace it should I get them to replace the seal again also? If it's leaking oil now will it stop once the diff can breathe?

It it were me - I'd ask that the seal be replaced again. With lower pressure - it may not leak, but the new one has leaked and it would be apparent to the mechanic.

The breather vents are not normally serviceable - they must be replaced.

(I own a 2015 Expedition Limited 4x4 and have previously owned other 4x4 vehicles).

 

[Trent_Au]

Thank you for your advice, I'll let you know how it goes.
Cheers

 

[99WhiteC5Coupe]

Thank you for your advice, I'll let you know how it goes.
Cheers

I did a little online research. Your model (if stock) should have a front differential vent hose, with the breather valve at the top of the hose.

I have seen where the vent hose has been dislodged (usually held to something with a plastic clip) and becomes pinched or melts if it falls against something hot. Make sure your mechanic checks the hose and its routing if he replaces the vent at the end of the hose.

After my last post - I realized where your location is. Greetings from the other side of the world.

 

[Trent_Au]

So we are originally from the Northern Territory of Australia, but we are traveling the US and Canada. We bought the expedition in Calgary Canada and have done almost 65,000kms over the past 5 months. Done every state in the US apart from Alaska, we've done coast to coast in Canada and now we are heading to NY for x mas. Currently in Maine where the car is hopefully (fingers crossed) getting fixed today. The expedition has been unreal, this is the one and only issue I've had with it, it's been in all extremes from 40*c to -30*c, snow, ice, rain.

 

[99WhiteC5Coupe]

So we are originally from the Northern Territory of Australia, but we are traveling the US and Canada. We bought the expedition in Calgary Canada and have done almost 65,000kms over the past 5 months. Done every state in the US apart from Alaska, we've done coast to coast in Canada and now we are heading to NY for x mas. Currently in Maine where the car is hopefully (fingers crossed) getting fixed today. The expedition has been unreal, this is the one and only issue I've had with it, it's been in all extremes from 40*c to -30*c, snow, ice, rain.

Good luck - let us know what your determine.

I'm envious of your trips - it sounds like the trips of a lifetime. I've traveled a lot in the USA - and about several dozen trips into Canada - but nothing further than Toronto, after crossing into Canada at the Ambassador Bridge.

 

[Trent_Au]

So just got the car back, they replaced the seal again and checked the breathers, they are saying that the seal looks faulty. Breather was ok and working correctly. Fingers crossed it doesn't leak again. What are the chances of two different mechanics installing the seal wrong though? What other issues could cause the seal to fail?

 

[99WhiteC5Coupe]

So just got the car back, they replaced the seal again and checked the breathers, they are saying that the seal looks faulty. Breather was ok and working correctly. Fingers crossed it doesn't leak again. What are the chances of two different mechanics installing the seal wrong though? What other issues could cause the seal to fail?

Glad to hear the problem may be resolved.

Not sure what could cause two seals to leak - other than a burr or poor installation, or use of a poor quality seal. Was a Motorcraft seal used?

Enjoy your travels.