Oil leak from front differential vent tube

[GeneRL]

I have a 1997 Expedition 4X4 that has been pushing gear oil out the vent tube on the front axle.

Ford recommends (TSB Article No. 97-10-10) new axle tube assembly part number F75Z-4K206-AA with vent tube relocated to the top front of the flange that mounts to the differential. I have also read (on line) that this repair was performed and the problem persists.

Has anyone performed this repair?

Has it resolved the problem?

Temporary Fix: I have lengthened the breather hose and added a catch can, at least to stop the mess and to monitor how much oil is being pushed out over the course of a month. I am 9 days in. So far so good. I may add a permanent catch can that reroutes the oil back to the diff. I think the contamination to the oil would be negligible especially if the oil is changed at regular intervals.

Feedback from forum members is appreciated.

 

[gto78]

I have a suggestion, may be similar to what you already did. If it were my truck, I would connect a lengthened vent hose to the existing one, and make it run straight up about a foot or more and mount it somewhere under the frame. My idea is basically to build a snorkel out of a piece of rubber hose. As long as it's not tight and can flex/move around then it should solve all your problems. Any oil that pushes out will work it's way up the tube, but shouldn't come out. Then gravity will return it to the axle. I believe off roaders do this stuff to keep water out, they run the vent lines up into the interior, or just block it off completely.

I'm sure the vent is there to allow moisture in the air to escape when the oil gets hot, and prevents condensation from building and running down the interior walls.

 

[Blackwater]

I might throw you in a whole other ballpark but nonetheless it might help. Check for over heating in the front diff, water, and maybe a fluid change. Also are you pushing just 2-wheel drive or the a4wd? If a4wd make sure your tires are the same size all the way around, air pressure the same in all 4. My experience came from a all wheel drive Cherokee that I had two different size tires on front to rear. It started heating the front diff first and the gear oil was venting out. Few days later the rear then the t-case…………

 

[GeneRL]

Thank you Blackwater and gto78 for your reply.

The extended breather tube is about 20 inches longer than the original and the catch can is doing the job. No more mess. I'll check the oil level (in catch can) soon.

I have changed the gear oil just prior to the aforementioned fix.

I have new tires (265/75/16 Hankook DynaPro ATM RF10 and I am very pleased so far, great traction and low road noise) on it as of 1500 miles ago and before that all four tires were the same size and in fair condition.

The front diff is hot but not to the point of burning my hand and it is not getting hot enough to boil the oil, at least I can not hear any boil.

My Expe. is a 4x4 but it has the 2x option and is not all wheel drive. never the less the front diff. is moving whenever the vehicle is moving just the transfer case is disengaged.

Blackwater, did your Jeep have any damage to the front diff. as a result of the tire size? Did new tires resolve the problem?

Thanks again.