Catastrophic Rear Axle Failure on Highway - Help Needed

[Yossarian_123]

Apologies for the title and the overall tone of this post but my wife and I are petrified after an incident this weekend.  Fortunately everyone walked away, but we’re hoping for some guidance.  Excuse any technical errors as I’m no automotive expert, and please redirect this post if this is not the right place for it.

 

Background:  we purchased a new 2023 Transit AWD Ecoboost 148 High Roof in September 2023 after having it upfitted by a camper-van conversion company.  The upfit is fairly basic – roofing, flooring, a counter and fridge, portable battery pack, etc, so not crazy heavy – and included a lift kit and larger wheels & tires.  As far as we know, no drivetrain modifications were done.  Since purchase we’ve put ~4k miles total on the van including a 1k drive this past Friday to visit my parents.  No issues to note through this point.

 

Incident:  On our return trip to Sunday, we were about 10 miles into the drive doing about 55mph due to intense winds, when our rear end started bucking violently.  It started loud, then got VERY loud, lasting five seconds or a little more - felt like rolling over a deep rumble strip but only from the back end.  As soon as it stopped, we started fishtailing.  We ultimately spun 180* drifting across the left lanes and ended up in the plowed snowbank along the median, facing the wrong way.  Miraculously, no body damage due to the soft landing in the snow, but a burning smell was intense and the vehicle was immobilized – engine running but transmission in neutral.  State trooper showed up within a few minutes and called us a tow.  Wife and I sat in disbelief waiting for the tow to arrive.

 

Details:   When the tow arrived we peeked underneath and found the rear driveshaft had sheared off at the rear differential and was sitting on the ground.  Clean diff fluid seemed to be draining from the differential itself.  No noticeable damage to the diff casing was visible (again, I'm no expert).  The tow truck was able to pull the vehicle backwards onto his bed and the rear wheels rolled okay in reverse, but when we got to the tow destination he had to ‘shimmy’/slide the van off because both rear wheels would not roll forward.  There was a small amount of jiggle in the rear wheels while he was ‘shimmying’, which suggested to me that it wasn’t a locked brakes issue which would have allowed zero play in the wheels themselves.  As of writing, still not sure whether the wheels/axle is totally locked, or if it still does roll backwards.  Hours after we dropped the van off, there was still a strong burning smell coming from under the vehicle.  Based on the sound, the locked wheels, the smell, the sheared driveshaft, I’m thinking something in the differential broke and locked up on us.  I suspected a lack of lubricant but based on the clean dripping fluid at the scene and after, it seems likely the diff gear oil was still in factory condition.

 

Other notes:  Our cargo was minimal for the return trip – we were in town for our baby shower (wife is 7 months pregnant) and we were driving back with strollers, clothes, etc for baby, plus the bare-bones camper setup.  The Ford dealer now has my keys and is working to arrange transporting the van from the next-door parking lot into their lot; I have asked for frequent updates, pictures, etc but haven’t heard anything other than I now have a service ticket opened.  They are backed up after the brutal weather this weekend - might be weeks until they can look at it.  I presume at 4k miles the drivetrain is still under full warranty and the service manager indicated that should be the case.

 

My questions are:

1.      Has anyone ever seen or heard of something like this happening – particularly on a nearly-new vehicle?  Any ideas on what happened?  Could the cold weather have anything to do with this?  Is there something that I might have done wrong?  Could a lift kit have caused this?

2.      The local Ford dealer service manager was gracious enough and made it sound like this shouldn’t be an issue warranty-wise, but it seems to me this problem/incident should be escalated beyond the local repair department.  We bought this vehicle intending to use it as a family camper in the Colorado mountains… I shudder to think of the outcome had it been on a mountain road, or in heavier traffic, or a few months from now… it is going to take a lot for us to feel confident in this van again.    Is there likely to be some kind of investigation?  Who can or should I try to talk to at Ford or elsewhere?  How do I ensure I get answers during this process?

 

 

Thanks!

Edited February 21 by Yossarian_123

[HotRunrGuy]

I wonder if your pinion failure is in any way related to the front pinion failure that occurred on some F-150/Expi/Navi's last year, due to lack of heat treatment?

 

Wonder if the same vendor is involved?

 

https://www.nhtsa.gov/recalls?nhtsaId=23V128000

 

HRG

[RoadWeary]

I recently had something happen with the rear diff, and was looking to see if there were any TSB's or recalls out there, when I came across your post.

 

Last week the brand new 2023 Transit Cargo, high top (with less than a thousand miles on it), I was taking on a long run on the highway had the rear-end lock up.
The van was empty at the time.  When I lifted my foot off the gas, the rear started "moaning" in a cyclic, rise/fall fashion, then the wheels started skidding and hopping.

I managed to get to the shoulder.  It wasn't the brakes, and nothing snapped off.. but there was the smell of scorched lube.

 

I am wondering if something came loose in the housing, or something wasn't aligned and wore other parts til they failed.  
 

It was towed by flat bed, and I am now waiting to hear what the problem was.

 

[Yossarian_123]

@RoadWeary Curious to hear what you learned.  Sounds like a similar event.

 

Update from my side:  Ford dealer replaced the whole rear axle assembly under warranty.  I put 1,000 miles on the vehicle driving it home, and no issues.  As far as Ford cares, it's fixed.

 

That said, I didn't get a satisfactory answer on what happened.  The technician suspected that a gasket or seal on the rear diff gave out, and the fluid leaked out causing the diff to overheat.  I wasn't totally sold by that because I watched diff fluid draining out of the hole in the diff while the van was on the tow truck bed, but it does explain the result.  They also couldn't tell me why they thought that was the case, other than overheating looked to be the issue and a leaking seal could cause it.  I didn't see any gear oil anywhere the van had been parked, so if that's what happened, it happened suddenly.

 

Called Ford corporate - they told me to "work with the dealer".  Seems like I'm out of paths to go down unless anyone else is seeing the same issue or has any other ideas.

 

[Yossarian_123]

Another update:  Ford is now issuing a recall for this.  Apparently they have not been putting enough gear oil in the differential at the factory.  This is almost certainly what caused our incident.  Apparently this has been known for several weeks, and yet when I talked to Ford I got literally zero helpful information.

 

My van is now BACK at another dealer - 1,000 miles later, a grinding sound from the rear suggests our new axle is also damaged.  Since the servicing dealer didn't know about this, I'm guessing they under-filled the differential again.