Safety Recall 22S27 Rear Axle Bolt Fractures

[TMac]

As far as the "fix it with a better bolt" idea- that's a band-aid. I think you're addressing the wrong problem from an engineering perspective. I have seen pics of bolts snapped- meaning they were subjected to enough force to actually break them. I've also seen pics of bolts that seem to be bent. It's actually possible that any replacement bolt from Ford has been designed to bend rather than break so as to contain the rear diff and minimize damage.

Under both of these scenarios, that bolt is held in plane by a high durometer bushing. You can't convince me that the bolt broke before that bushing absorbed some fairly large rotational movement of the rear differential prior to the failure. I highly doubt given the current bushing that an "upgraded" bolt will solve the problem. I'd instead go for the AWR or ID speed brace which provides another bushed mounting point as well as balancing the load horizontally across the rear of the diff.

You should also try to eliminate wheel hop- the violent wind-up followed by an unwind event will break just about anything.

 

[Cajun Heat]

As far as the "fix it with a better bolt" idea- that's a band-aid. I think you're addressing the wrong problem from an engineering perspective. I have seen pics of bolts snapped- meaning they were subjected to enough force to actually break them. I've also seen pics of bolts that seem to be bent.

Under both of these scenarios, that bolt is held in plane by a high durometer bushing. You can't convince me that the bolt broke before that bushing absorbed some fairly large rotational movement of the rear differential prior to the failure. I highly doubt given the current bushing that an "upgraded" bolt will solve the problem. I'd instead go for the AWR or ID speed brace which provides another bushed mounting point as well as balancing the load horizontally across the rear of the diff.

You should also try to eliminate wheel hop- the violent wind-up followed by an unwind event will break just about anything.

Do you have anything that you would recommend to reduce/eliminate wheel hop?

 

[TMac]

Do you have anything that you would recommend to reduce/eliminate wheel hop?

First would be not launch as violently (yeah, nobody wants to hear that). Put on less sticky, or way more sticky tires (you probably don't want to hear that either!) Barring that, you'd have to find some way to lower the amount of deflection in all the suspension pieces related to rotational movement.

Let's face it, the average ST has nearly 160 lbs of wheel and tire in the rear plus the mass of the brake rotors. When that mass loads and then unloads all the various bushings meant to give you a somewhat silent and cushy ride, something has to give.

 

[Cruising68]

I’m guessing with the two bolts you are virtually eliminating that rotational stress on the bolt and bushing by spreading it across two points. Also guessing that significantly reduces the deflection in the bushings as rotational force would result in upward movement of one bushing and downward movement of the other, no?


Sent from my iPhone using Tapatalk

 

[TMac]

I’m guessing with the two bolts you are virtually eliminating that rotational stress on the bolt and bushing by spreading it across two points. Also guessing that significantly reduces the deflection in the bushings as rotational force would result in upward movement of one bushing and downward movement of the other, no?
Sent from my iPhone using Tapatalk

Theoretically if the load is spread across the horizontal axis of the differential proportionately, the stress on each mounting point is cut in half, so you're right. However, the differential under acceleration is attempting to rotate in the opposite direction of the wheels, so both bushings see the same force in the same direction.

But that only addresses the differential. In the case of wheel hop, you still have the rest of the suspension assembly (half-shafts, ring/pinion, A-arms, etc) that are subject to the whipsaw motion.

But honestly, spinning is not winning, so if you're hitting wheel hop or spinning the tires at all, you're not netting the best dig.

 

[Dale5403]

One issue I would be concerned about if using an ARP stud is warranty. Should it break my guess a person would be on the hook for repair as it's not an OEM part that broke. I could be wrong but just something to think about.

 

[SimonsGTS]

I've had an automatic e-brake such as this one on my last 2 Ford products since 2015. I always use it when I park and I NEVER use the button to release the brake, ever. It's designed to release as soon as you tap the throttle. My Fusion Hybrid at work also does the same thing. No big deal! I think some people just miss the old days of cranks and levers and loud noisy mechanical things.

Yes I've also used the throttle release method before and it works great, but I'm one of those people who just miss the old days of cranks and levers and loud noisy mechanical things lol!

 

[bosephbarking]

Anyone taken delivery of a 2023 yet? Wonder if this has been fixed or I should be preemptively installing an AWR-E3301?

Just got to crawl under mine. 2023 blend Dec 12 has the 3 bolt version, dealer got a 2023 with a late Nov blend date with the 4 bolt. There is clearly no rhyme or reason to which they choose. Both are ST 401A package.

 

[Delmustator]

I'm definitely gonna crawl under it and check it. I'll report what I find.

My 2023 has two bolts..

 

[Bordaine]

I looked today

 

[hbalek]

I looked today
View attachment 16206

Unfortunately I can't see mine anymore because I had my dealer order and install the missing air deflector back in April 2020, which was left out of many of them. I like having the cleaner look behind the bumper with that black deflector but now I can't see what you're showing but I have photos from before the install so I know I had 2 bolts at production time. Hmmm, maybe Ford deleted the air deflector so they could easily inspect rear bolt damage. (conspiracy theory) LOL

Before and after:

 

[Cruising68]

Nice to see they at least fixed it moving forward......while leaving a lot of people hanging out to dry.

 

[FORZDA3]

Yeah, haven’t seen the firestarter guy crapping on these failure threads for a while now. Maybe his head exploded over Ford actually fixing this problem, but on the sly. Still not sure why they screwed it up in the first place…

 

[Boss240]

They need to get us 3 bolt people a proper fix too by upgrading us to the 4 bolt

 

[R2D2]

I had my dealer order and install the missing air deflector back in April 2020,

Do you have the part number?
This is for aerodynamic improvement?

 

[bobter3]

Do you have the part number?
This is for aerodynamic improvement?

L1MZ-7811778-A Under Cover
W714040-S300 Wheelhouse Liner Rivet (2 qty)
W715060-S450B Screw & Washer 4.2 x 25 mm (4 qty)

 

[Waters]

Sad day. Watched a valet throw the ST in reverse, gave it too much gas, rev'd, ST auto released the parking break, chirped, and they nearly slammed into a building. Traded it in the next day. Expedition SPP. Not my favorite, but feels much more secure than the rev'ed up parking break release.

 

[hbalek]

Sad day. Watched a valet throw the ST in reverse, gave it too much gas, rev'd, ST auto released the parking break, chirped, and they nearly slammed into a building. Traded it in the next day. Expedition SPP. Not my favorite, but feels much more secure than the rev'ed up parking break release.

LOL

 

[TheHypnoToad]

Since the ST was at the dealer for routine maintenance, I gave the tech the part number for the two bolt rear subframe and asked for a cost estimate for replacing the current one bolt one with the two bolt one. Answer came back that their “transmission expert” looked and said that “you can’t replace a three bolt rear end with a four bolt one”. Started to call BS but just said “news to me” and assumed that they didn’t want the job. They did say that if the bolt did break, they would look into fixing it under warranty. Gotta love Ford Dealer Service Departments.

 

[viking]

Since the ST was at the dealer for routine maintenance, I gave the tech the part number for the two bolt rear subframe and asked for a cost estimate for replacing the current one bolt one with the two bolt one. Answer came back that their “transmission expert” looked and said that “you can’t replace a three bolt rear end with a four bolt one”. Started to call BS but just said “news to me” and assumed that they didn’t want the job. They did say that if the bolt did break, they would look into fixing it under warranty. Gotta love Ford Dealer Service Departments.

What is the part number for the "All Bolt" subframe (some call it 2 some call it 4) I have a 22 build with missing rear.
I'm going to stop by my local dealer for some parts and I will pose the same question to them just for fun!!