Looks like another axle bolt shear…

[SaSurvival]

Definitely seems like shear. Looking at the bolt I’m guessing it was compromised at the install and then corrosion and operational vibration finished it off. This would explain why it was not seen on the assembly line.

However I know how their assembly line works. I guarantee that Ford has the installation torques documented for these axle nuts with their DC tools for ever truck manufactured. So it will nust be a matter of reviewing th

I suspect their was an error in the torque call out for their standard work and they didn’t adjust it until later on. However, I don’t know why this wasn’t caught with the initial 2021 model builds. This means that there are now thousands of impact trucks out there.

Wouldn’t want to be the engineer responsible for that oops.

Does anyone know what rough production dates this issue concerns? We tow regularly with our 2022

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[Ries]

If it was an over torque situation it would be a tensile break, not a sheer break.

I was initially thinking that it was a preload/setting issue and then the operational forces caused a shear failure.

However, looking at the bolt again in further detail it is not a shear failure. I’m now thinking this is something to do with an interaction tire slipping and shock loading on the axle, caused the fatigue fracture failure on the bolt.

I have been driving a lot in the “slippery” drive mode because of the snow and ice this winter. I’ll be curious if this played a roll in the failure with how their programming handles power transfer.

 

[SaSurvival]

Does anyone know what rough production dates this issue concerns? We tow regularly with our 2022

Please disregard the above Q, I kept reading the thread and found the answer sorry about the Q.

 

[Pedaldude]

...miles when failure occurred is never exactly known

Been driving around with the center caps removed and check every time I get in and out of the truck.

Knowing within 1-12 miles of when/if the bolt breaks isn’t really going to help much other than knowing that just replacing the bolt shouldn’t be an issue.

 

[Ries]

Been driving around with the center caps removed and check every time I get in and out of the truck.

Need to get some clear center caps

 

[tony72cutlass's']

Need to get some clear center caps

 

[MikeyDog]

Would it make sense to replace the 10.9 bolt with a harder 12.9 bolt?

 

[Farmerj]

I’m thinking that the center of the washer needs to be opened up so it’s not tight on the bolt threads

 

[HeadBanger]

From the post listing the chart above, it's stated that these are all trucks with the Max Tow option. Is that the case? I have the tow package, but not the max tow.

 

[Buyer2021]

From the post listing the chart above, it's stated that these are all trucks with the Max Tow option. Is that the case? I have the tow package, but not the max tow.

ONLY Max Tow package has the 3/4-float axle which is subject to this failure.

 

[Ries]

I’m thinking that the center of the washer needs to be opened up so it’s not tight on the bolt threads

I saw that they are using some kind of hardening sealer when assembling it. When I removed the bolt head I actually had to unthread it from the washer. If that sealer wasn’t hardening there should be enough clearance.

 

[Porpoise Hork]

I’m thinking that the center of the washer needs to be opened up so it’s not tight on the bolt threads

The hole on the washer has a rubberized compound that prevents it from slipping off the bolt and does not come in contact with the bolt shaft. It only contacts the bolt head when it is torqued down.

 

[Farmerj]

ONLY Max Tow package has the 3/4-float axle which is subject to this failure.

HDPP does too.

 

[Buyer2021]

I saw that they are using some kind of hardening sealer when assembling it.

Please, who is "they" and what / where is this "hardening sealer" you reference?

The Ford Workshop Manual R&R procedure (attached) does not call for any sort of "sealer" in this assembly; the bolt as supplied does have pre-applied thread locking compound.

 

[Porpoise Hork]

Please, who is "they" and what / where is this "hardening sealer" you reference?

The Ford Workshop Manual R&R procedure (attached) does not call for any sort of "sealer" in this assembly; the bolt as supplied does have pre-applied thread locking compound.

If this is in reference to the thread locker, the bolts do have pink/red thread locker applied to them.

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