'12 Expy EL Rear diff leak
 

So, not that old of a rig, 18 mo old and just over 20,000 miles. Problem is, we have had the rear differential seal replaced 4 times now (Left side). 1st seal around 9K miles, 2nd around 9800, 3rd at 19,900, 4th done today at 20,800. This is a large dealer, running day and swing shifts in their service center. All repairs to date have been done under the same "team's" care. I do not know if that means the same technician too, I had not bothered to look that up.

We do tow a travel trailer about 1-2 times a month, typically around 200 miles round trip over "flat" terrain some weekends, or mountains the others. We generally stay at or just above the speed limit towing the trailer loaded between 6500-7500 lbs. Trailer sway control and weight distribution is used putting between 400-500 lbs to the front of the truck. It handles it well, far better than our 2006 expy used to.

Anyone had repeated issues of seal failure in the rear diff? I'd like to know how often they fail, if you are towing/hauling, how many miles a year? I am trying to get an idea of whether or not this truck should be used for this much towing. Really wanted an Excursion, but this is the wife's rig. Now I get to deal with the potential inadequacies...:-banghead

Thanks!

Lewis

They are treating the symptom not the root cause. Something is making the seals fail, if it happened once you could say bad seal or bad assembly, but not repeated times. You use isn't unusual.

I checked it again last night.... Cleaned it up so that the diff is dry. Wife went to the store, there is another drip of gear oil hanging out on the bottom of diff. They said they cleaned it up. Either they didn't, did a really bad job, or the stupid thing leaks like a sieve. Even though this $h1t is under warranty, I feel like I should just do it myself to know it is done right and eliminate the variable of others incompetency. How difficult is it to get Ford to step up and put in a whole new differential?.

Did they check the vent tube? I wonder if the axle shaft has nick in it or something allowing it to leak even with the new seal.

Yep, make sure that the vent breather isn't plugged. get the dealer, or yourself if you have an air compressor, to put some compressed air in through the filler plug and make sure that the pressure bleeds off on top where the breather is. If that is plugged, when you drive and the fluid heats up and expands, it will force its way out, either the output shaft seals or the pinion seal. if it is plugged, gear oil will spit out of the fill plug when you remove the blow gun