2016 Exp. TWO Differential repairs in 9 MONTHS

[ammcf1]

2016 Expedition EL - I'll try to keep this brief

My family and I travel full time in our RV and flat tow our Expedition behind our motor coach. We are very careful to use the factory Neutral Tow mode properly. No mishaps have occurred there.

We have owned the vehicle since late 2016, and began pulling it behind our motor coach in December of 2018.

Back in May of 2019 I was hearing a slight grinding/humming when I made turns. I couldn't tell where it was coming from. Took it into a Ford Dealership (Joe Machens Capital City - Jefferson City, MO) and it was diagnosed as "Rear Differential clutches worn and binding." I had that repair done and the noise was gone.

In January 2020 (8 months later) I began hearing a similar sound. I took it into a Ford Dealer (Phil Long Motor City - Colorado Springs, CO) and it was diagnosed as "Bad rear ring and pinion and all internal bearings." Looking at the invoice, they replaced the differential bearing assembly, shaft repair kit, gear and pinion asy, and slinger. Once again, the noise was gone.

Here we are in late September, early October 2020 and I'm hearing the noise again!

I'm wondering what's going on with this? Why would this kind of thing be happening over and over? It's getting pricey!

ONE THEORY: Could it be possible that something about the way the factory "Neutral Tow" setting works isn't really working? That IT is faulty in some way, causing this issue to recur? (I don't know anything about how it's all connected, but it's my current theory)

When I put it into "neutral tow" mode I hear the click and the dash panel indicates it IS in the "neutral tow" mode. When I disengage it, the dash panel says it's disengaged and it drives normally.

Any of you pros out there have any ideas?

[Stealthee]

I unfortunately don't have any theories to help you on if the neutral tow mode is the culprit, but one thing I can tell you is that the shop truck for a company I used to work at (2016 F150) had the rear differential bearings fail at less than 90k miles. maybe there was a QC issue at Ford or whoever the supplier of the rear diff was.