[FanaticalKilla]

So the skipped an easy machining process. Taper and a keyway would have made it bulletproof. 1-2 thou splined shaft probably doesn’t come apart nicely anyways.

 

[EcoXLT]

My mind goes to it’s like that one bolt holds a lot of pressure and it takes 6 bolts to hold the rim to the axel flange. 4 bolts to hold the bearing hub to the axel tube. I know the physics are different between the three but that’s what spins in my head.

 

[snakebitten]

Ironically, that bolt doesn't really have any purpose but to "locate/hold" the position of the axle sitting between two splined ends. Visually, and on paper, it shouldn't really be stressed to a breaking point. Not at all.

But it appears in reality, the amount of "flex" in the wheel bearings does in fact put a constant radial stress on the shoulder of that bolt and it can fail under fatigue.

The one constant for these sheared bolts is they fracture in the same place, relative to the head.

 

[Gord0]

Ironically, that bolt doesn't really have any purpose but to "locate/hold" the position of the axle sitting between two splined ends. Visually, and on paper, it shouldn't really be stressed to a breaking point. Not at all.

But it appears in reality, the amount of "flex" in the wheel bearings does in fact put a constant radial stress on the shoulder of that bolt and it can fail under fatigue.

The one constant for these sheared bolts is they fracture in the same place, relative to the head.

Could have probably just used something closet to the same C clip design as the standard axle.

 

[FanaticalKilla]

Put one on each end of the tapered bearings. With shims to take up machining tolerances is so needed.

 

[snakebitten]

I'd be thrilled if the crystal ball revealed to me that in the first 100,000 miles of my 2022 F150 Ecoboost/Powerboost, the most serious issue that I would contend with is a sheared Max Tow axle bolt.

It's relatively inexpensive assembly. (axle/hub) and the book time for replacement is minutes, not hours. (~30 minutes per side)

Besides, I've already experienced it, under warranty, and it was low drama relatively speaking.

 

[Mokehill]

I picked my truck up yesterday and all they replaced was 2 axle bolts and the broken axel. They did not replace the hub on the broken side like @snakebitten mentioned they did on his truck. Another issue I'm having is the transmission has a shudder in 4th and 5th gear, I mentioned this to the service adviser who was working my truck, she said I should take it to the dealer where I live because it could take weeks to fix. That's why I mentioned I would be looking at different manufacturers. I test drove a couple different trucks and I just can't switch, my truck drives so nice compared to the others. Now looking at 2025 3.5 EB without MAX TOW.

 

[snakebitten]

That's crazy that they wouldn't replace the axle/hub assembly. It's literally a part# and comes press-fit. In my opinion, if the bolt shears, the press-fit splined surfaces are almost guaranteed to "fret". (if driven much unwittingly) So the new axle splines will be mating to a compromised aluminum hub spline. Or put another way, it almost insures it to not have the expected lifespan.

Ford clearly states in their documentation the part #'s to use if/when the bolt shears. It's the assembly.

 

[boosted1469]

If I'm ever in this position because I plan on buying a 21 or 2235 which all three point five EcoBoost have the 9.75 rear end not sure if they were all semifloat or not is I would call ARP and have them make me a bolt for that It would obviously be 10 times stronger than a grade 8. They have both with up to 200,000 lb of tinsel strength

 

[snakebitten]

There are 2 different 9.75 axles.
Different designs.
The 2021-2023 Max-Tow axle is the culprit.
Non max-tow, no bolt to shear.

 

[snakebitten]

Someone discovered that Dorman has a replacement axle that they claim addresses the issue. It certainly looks like it might.

$252 on Rockauto

 

[bluelight]

That Dorman shaft kind of looks like the old AMC 15.

 

[boostkingMatt]

The bolt is garbage, in my opinion.
And I also think the torque spec is beyond what a 12x1.75 grade 8 bolt should be.

Again, just my opinion.

Like I said earlier, I replaced mine with an aftermarket bolt torqued at 84ftlbs. Added the Bellville washer for some "give", if you know what I mean.
It's le$$ than $10
No way am I letting go of the most amazing 1/2 ton truck I have ever owned because of the shortcomings of Ford to address the fix.

10 new axles wouldn't cover the co$t of depreciation, just to make a point that Ford would never even feel.

How do I check to see if my truck has that bolt too?

 

[snakebitten]

If you have a max tow rear axle, you have the bolt.

Pull your wheel or center cap and see if there's a bolt head in the center of the axle. (picture on the left)
The recall is replacing the axles with the one pictured on the right. (identical to the Dorman designed axle in the previous post)

 

[miniceptor86]

Ironically, that bolt doesn't really have any purpose but to "locate/hold" the position of the axle sitting between two splined ends. Visually, and on paper, it shouldn't really be stressed to a breaking point. Not at all.

But it appears in reality, the amount of "flex" in the wheel bearings does in fact put a constant radial stress on the shoulder of that bolt and it can fail under fatigue.

The one constant for these sheared bolts is they fracture in the same place, relative to the head.

Like work hardening which makes the metal brittle.

 

[F150brokenaxles]

I lost drivability when my axle failed suddenly, no warning, hi risk area, 65 mph in the rain. worse I had to wait for the police to stop traffic in my lane because I was in a tight breakdown lane. This failure occurred with replaced interim axles. I encourage anyone who has been in danger or at risk with this recall to file with the NHTSA. I‘ve always loved Ford. They are a good company but this has caused a lot of problems and it’s 10 weeks now of loss of use.

 

[snakebitten]

Ford currently is replacing the MaxTow axles via a recall. (new design)
The loss of drivability from the sheared bolt on the oem axle is fairly rare, although the sheared bolt isn't.
I sheared one on the passenger side and Ford replaced both axle/hubs with the original design. They've been fine, but at some point I will schedule the replacement for the new design.

 

[RossRR]

I lost drivability when my axle failed suddenly, no warning, hi risk area, 65 mph in the rain. worse I had to wait for the police to stop traffic in my lane because I was in a tight breakdown lane. This failure occurred with replaced interim axles. I encourage anyone who has been in danger or at risk with this recall to file with the NHTSA. I‘ve always loved Ford. They are a good company but this has caused a lot of problems and it’s 10 weeks now of loss of use.

It should not be ten weeks loss of use. I'm sure Ford will prioritize your vehicle for the new axles. My dealer set me up for the recall replacement axles, had them in four days and had me in two days later on May 19th for the recall work. I sat in their waiting room for an hour and fifteen minutes and was back out on the road again with the new axles. If your dealer is sitting on your truck, I'd give him a call and read him the riot act.

 

[Boatwaco]

I think a dozen donuts for the service manager is way past due.

 

[Upshifter]

I think a dozen donuts for the service manager is way past due.

Generally sage advice, but in this case Ford should be giving him the donuts.

Need to draw a line between engineering failures that cause inconvenience vs. life threatening accidents.