As @RossRR has asked, Have you reported this failure to the NHTSA.GOV stating the the dealer is holding the truck because "it is unsafe to drive"? If enough people report the failure, Ford will have to deal with it proactively. (Another failure was reported on the other forum after you reported yours)
It isn't always that easy. If a change to the material or specifications was made then the part number will change. If they were defective/didn't meet specifications...and the ones now available meet all specifications or come from a different vendor then there would likely be no part number change.
The bolt shearing or even if just plain missing wouldn't cause any drivetrain slack, the Raptor doesn't even use this axle design, and the 3 vs 1 bolts explanation is nonsense. I think you had a different problem. Does your truck have the Max Tow Package?
You are welcome to your opinion. I'm only conveying what I was told by the service Dept. I asked to see the axle but by the time I was able to pick up my truck, I was told that the part had already shipped to be returned to Ford.
yes it does, XLT Crew, short bed, max trailer tow, 3.5 PB
and locking rear diff
Seems like based on all the other posts it’s related to the max tow pkg floating rear. Still seems strange that where a bolted joint is loaded in shear in a drivetrain engineering would allow a single point failure.
RossRR
The subject bolt is not loaded in shear (it is not loaded perpendicular to the axis of the bolt). It retains the splined axle shaft in the splined bore of the mating wheel hub, so the bolt is loaded in tension (loaded parallel to the axis of the bolt).
Thank you for the info and picture. So either substandard material or bolt preloaded beyond recommend preload. So I‘m assuming that when the bolt fractures the axel is allowed to slide towards the diff and then disengaging the splines, correct? Truck does not move when this happens (at least in my case) other than when 4 wheel drive is engaged or maybe diff lock (which I did not try). Thanks again for the info.The subject bolt is not loaded in shear (it is not loaded perpendicular to the axis of the bolt). It retains the splined axle shaft in the splined bore of the mating wheel hub, so the bolt is loaded in tension (loaded parallel to the axis of the bolt).
Forces perpendicular to the axis of the bolt / axle / wheel hub centerline they are borne by the bearings/wheel hub/4 bolts holding the wheel hub to the axle housing and /or the axle shaft itself. That's why the wheel does not fall-off immediately upon failure of this single bolt, there are redundancies in the connection, both parallel and perpendicular.
Pic from this thread on another forum showing the splined hub, the end of the splined axle shaft in the bore of that hub, and the broken retaining bolt with washer:
FWIW from the several threads on 2 forums that I'm following on this topic I'm not aware of any other reports where the failure of this bolt has actually resulted in 'no drive' at the rear axle, nor any cases where it's been reported that the axle shaft has slid far enough inboard to disengage the splines at the hub.
