Hey all,

Been fighting a front end noise on the '17 3.5eb 157" 4x4 Lariat. Truck gets a low pitched/frequency growl that can be felt through the steering wheel and floor pan. It's been intermittent but becoming more frequent.

Took it into the dealer this morning, and the shop foreman said he wouldn't even bother doing a ride-along, that what I've described sounds like a front differential issue they are working on diagnosing on a couple trucks in the area. Given the noise and occurance of it (usually when I'm unloading the driveline by coasting) and giving a quick search to the forums here I tend to agree with the diagnosis.

https://www.f150forum.com/f118/2016-...lready-323332/
https://www.f150forum.com/f118/4x4-4...288521/index2/
https://www.f150forum.com/f4/loud-cl...engaged-19877/
etc.. etc...

A couple questions I've got:

1) Is there a different front diff based on wheel-base? With the 157" I would be working the front diff harder to make the same radius turns as a shorter wb truck. Is it possible the wrong diff made it into the truck?
2) With the 4A systems in the Lariats, would failing IWE's lead to unintended drag on the front diff causing damage?
3) Is there another upstream failure where the 2H drive wouldn't disengage the front diff properly, again causing undue wear and tear on the differential?
4) Has anyone had 15+ front diff's replaced providing resolution to the issue, or is there an upstream problem that I should ensure Ford is resolving as well?

Thanks!

 

An issue with the IWE system would create the symptoms you describe, and also a sensation of drag in the left front. I had the IWE changed under warranty and it seemed fine, but a week later it occurred again. So...I installed check valve YG360 available in series with the factory one, and (knock on wood) has been fine for 2 months. I did also change the solenoid and check valve a few weeks earlier, so I did know that wasn't the issue. It seems the aftermarket check valve is a better design/material than oem. It will say the part will not fit when you look for it on Amazon, but its snug and will fit. For the $8, do it.

 

Interesting, so you installed another check valve right after the original? I have the noise on my 2015 and have a new valve from Amazon.... instead of replacing the one i have, i should just add the new one?

 

OK I'm not sure this applies but. I asked a highly recommended service manager about the 2 speed transfer cases (when I was ordering my truck) and he said they were fine but they often have to regrease them and then work fine.

 

 

There has been a rash of pinions not being properly tightened, and over time cause wear in the ring and pinion. That is what happened to mine, and they said it was not the first, in fact it happened enough times they knew what the issue was before driving it. What kills me, I rarely if ever had used 4WD, which means the IWE's were engaged for quite some time in order to destroy the front diff, it was replaced around 26K or so. I have had both IWE, and all related components replaced and they are still engaging on their own.

As far as 4A, that is just the transfer case, the front diffs are the same in all 4WD truck, only difference would be the gearing.

Because of all the crap I have gone through with my 16, my next truck will be RWD once again. Snow tires worked wonders on it and far fewer items to go bad.

 

If you want to install another in tandem, this is how I did it, might be overkill.

 

Ford ended up replacing/rebuilding my 2016's front diff, and later, both IWEs. I had a front end noise that initially sounded like a rattle and later turned into a growling sound until the drivetrain warmed up. Turns out, one of my IWE vacuum hoses was missing resulting in one IWE locked and the other unlocked. That resulted in gaulding of the internal differential parts which necessitated the rebuild. About 10 months later, I heard the tell-tale grinding of IWE failure, which my dealer confirmed. Both IWEs were replaced. I assume this was all related somehow, but my dealership said the IWEs are known weak link in the truck so maybe yes, maybe no. Everything was done under warranty, so other than the frustration of replacing a front diff at 12k and IWE's at 24k, it was handled well by Ford. All is well now ... no noise, smooth/complete engagement/disengagement of 4WD (I have a Lariat with 4A too), and hopefully I've seen the last of this.

 

I have a 2017 with the same exact issue. Just went to a dealer this week, they knew right away and said IWE so I thought great, lets fix it. After a quick test drive the service guy said sorry we didn't hear it so I can't do anything. After searching around this seems to be very common problem and most the time "IF" the dealer replaces them it returns.

 

IWE.

Dealer will most likely not do anything and tell you it's fine, after running a battery of tests.

Very hard to replicate at the dealership since it happens randomly. I wasted a few days during winter with that. Next time it does grind, I'll floor it until it breaks completely. That way, I'll get new parts for sure.