Cracked Front Diff Housing

[Pedaldude]

Odd question, had you applied significant power while in reverse while in 4x4?

I guess not an odd question after all. Is that the mode that most of these diffs have failed under?

I exercise my 4X4 once a month, either in the alley or a dirt lot but the only time that I have needed 4X4 is backing a trailer up an incline.

How different are these differentials from the previous generation?

The brace mentioned above works all the way back to 2015; so was this a design issue then under extreme service and it’s being exacerbated by a bad lot of castings?

https://www.vasfab.com/product-page/vas-f150-15-20-4x4-front-differential-brace

I could see warranties being denied for having the brace, even if it kept the failure from happening sooner. Also, if the castings are bad; I would rather it fail under warranty than spend $200 to have it fail later.

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[powerboatr]

I was in 4H, in reverse, tires were spinning, tires caught traction and boom, no More 4X4.

that could have put enough stress on housing, pop goes a flaw
tires spinning how fast and GRAB and something has to stop
i would want to see the casting then clean it and take it to a NDI place and see if they see any presumptive flaws...thats the engineer in me

 

[hotrodmex]

Is that the mode that most of these diffs have failed under?

I'm pretty sure the first two from f150forums were in reverse when it failed. The guy with the lift kit definitely, the other maybe after a period where he had.

Reverse is where the diff is weakest.

Also note this is another '21.

Concern here from a '22 4A where I can't disengage the front diff without eIWEs.

 

[powerboatr]

I'm pretty sure the first two from f150forums were in reverse when it failed. The guy with the lift kit definitely, the other maybe after a period where he had.

Reverse is where the diff is weakest.

Also note this is another '21.

Concern here from a '22 4A where I can't disengage the front diff without eIWEs.

that could be hairy out in the sticks

 

[PPK]

An aluminum case taking the brunt of 300 hp.. really is going to give. It might be that the lariat and up transfer case limits the torque due to clutch in the case slipping.. in theory probably keeps the torque down in low range.. but a high speed bind.. don’t know. 300 hp is a lot for an aluminum case. There may be torque limits on the engine too, but you get a crank/drivetrain spinning up, there is a lot of energy to dissipate... its not the fall that hurts. Its the sudden jolt at the bottom…

 

[hotrodmex]

300 hp is a lot for an aluminum case.

*Mustang has entered the chat*

 

[Chease44]

Wow I just found this thread after it being mentioned in another one about the front diff cracks. I half ripped the transmission diaper off my truck during the first real snow fall we had this winter. When I drove it up on ramps at work and removed the diaper, while under there I noticed the cross member looked wet under the front axle. I thought it looked like the pinion seal was leaking but I guess I need to have a better look. Does anyone know what colour the front diff oil would be? Last winter after a very heavy snow fall I had red fluid under the front of my truck, couldn’t for the life of me figure out where it came from.

 

[SRHAGEN]

An aluminum case taking the brunt of 300 hp.. really is going to give. It might be that the lariat and up transfer case limits the torque due to clutch in the case slipping.. in theory probably keeps the torque down in low range.. but a high speed bind.. don’t know. 300 hp is a lot for an aluminum case. There may be torque limits on the engine too, but you get a crank/drivetrain spinning up, there is a lot of energy to dissipate... its not the fall that hurts. Its the sudden jolt at the bottom…

How do the snow plows do it I wonder. I think the coyote is 400 but not at the transfer case I’m sure. Maybe that’s why u have to order a snow plow package. Back and forth on the gas lotsa torque.

 

[Ryan74]

In addition to the two people now in this thread, there have been two on another board. I'm sure there are more out there, like the MaxTow axle bolts.

One user had a 4" lift so they denied his claim (shout out to Rough Country for the auxiliary warranty actually being worth something, though.), but the other user was stock height, no modifications.

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To deny a warranty claim doesn't Ford have to prove that the 4" lift is what caused the failure?

 

[SRHAGEN]

To deny a warranty claim doesn't Ford have to prove that the 4" lift is what caused the failure?

if you build 1000 and 10 fail it’s not really a defect. Just QC

So much for the magnussen-moss act. I think it’s called.

 

[hotrodmex]

To deny a warranty claim doesn't Ford have to prove that the 4" lift is what caused the failure?

They only have to "prove" it if you actually sue them about it, otherwise the dealer makes the determination and Ford accepts it or doesn't. In the case of you cutting the frame for a 4" lift, pretty sure it'd be a slam dunk in a courtroom to prove the components were altered well outside of design spec.

 

[SRHAGEN]

They only have to "prove" it if you actually sue them about it, otherwise the dealer makes the determination and Ford accepts it or doesn't. In the case of you cutting the frame for a 4" lift, pretty sure it'd be a slam dunk in a courtroom to prove the components were altered well outside of design spec.

I d say the Act doesn’t apply to frame modification and agree with you. It’s just for oil, spark lugs, filters, shocks stuff like that.
Most aftermarket companies do warrant there stuff. It says allot about rough country to stand behind there products.

I do know what ur sayin, if the dealer says no. It ain’t no fun trying to change the minds. Truly a uphill battle.

 

[EricR]

Small Claims Court is an option for denied warranty claims of a few thousand dollars or less.

I would be surprised if Ford even showed up.

 

[DT400]

Definitely, well my opinion anyway, a design or casting/metallurgy issue.

As far as I know this isn't a load bearing component like a solid front axle truck I haven't looked under my '22 F-150.
Spinning the tires and having them grab takes out axles, not diffs ( at least it shouldn't in a properly designed/cast diff). Reverse vs forward with one being stronger isn't a housing issue it has to do with whether or not the ring and pinion are being operated on the coast or drive side of the teeth where you could break teeth off.
In the decades I have been 4 wheeling I have broken many axles, front and rear, but the only time I have seen a diff housing break is when a MAJOR impact has happened...and you'd know it no question.

Pretty disconcerting at any rate.

Darrell

 

[Rippy]

My 2021 started to leave an oil puddle in my driveway. I took it to the dealer this morning, and after a couple of hours of searching, they found a hairline crack in the front diff housing. They mentioned the cold and snow as a potential cause, but still covered by warranty. Has anyone heard of that before?

I had the same problem at 17k miles. Replaced on warranty but just found out the new one has the same problem at 24k. Dealership ordered new parts and will repair when they fix the three outstanding recalls…..

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