Several weeks ago, I traded my 100k-miles 2005 F-150 in for a new 2014 model of the same truck.

The new truck now has 1500 miles on it and is making some worrisome noises when it is in 4WD. I live at 8200 feet above sea level, and snow and ice are a regular occurence up here. I need 4wd quite often.

But back to the noises...

It makes a sort of growling/grinding noise out of the right side when the front wheels start to slip on ice and a faint scraping noise on the left as it is going down the highway - until you turn off the 4wd and then, after a few seconds, I hear a clunk and the scraping noise goes away.

Thinking back, I had almost the exact same noise occur when my 2005 was about 6 months old and again at around 90k miles. In both cases, the problem turned out to be the vacuum-operated locking hubs had an inconsistent vacuum signal -- causing them to partially engage. The first time it happened the dealer described the problem as a "vacuum leak" and the second time it was attributed to a vacuum solenoid that had gotten wet and corroded -- again causing a vacuum leak. I had to do the research myself and took a copy of the TSB to the shop to show them that the problem had been documented by Ford back in 2006.

I thought surely, Ford had updated the design to avoid these problem - but after some research -- I found they use pretty much the same system for the 4x4 -- 10 years later (started using it in 2004). Service bulletin and earlier repairs notwithstanding, I had to pay for the repairs that time.

My question for all of you is: If this is a chronic problem on F-150 4X4s, why hasn't Ford figured out a permanent fix? Obviously, it will go back to the dealer for warranty repair, but I am frustrated that after a decade of use -- Ford still has this problem on otherwise wonderful trucks.

 

Howdy.

General Weaknesses:

1. IWE's

1a. vac lines to front wheel hubs

2. 8.8" front diff & puny front half-shafts & CV's.


Items 1 & 1a: can be largely mitigated with exemplary preventive ( not reactive) maintenance, regular 4wd system exercise, and regular inspections.

Item 2: we can only live with - worrisome mostly to folks who like to do 4wd WFO drag launches, and have an EB spooled up. 5sloh fellers needn't worry as they don't have the requisite tq to begin with

MGD

 

This description sounds like maybe traction control is engaging... do you get the traction control light on your dash?

 

No...no warning lights at all. Pretty sure it is a leaking IWE system. My 2005 made the same noises and both times, it turned out to be the vacuum hubs.

Just read another post on a similar problem. His 2012 bogs down...as does mine whenenver the front wheels start to slip. Makes a terrible noise, too.

Thanks to all who've responded!

 

I have a 2012 4x4 with the 5.0 and around 10000 miles I had the same sound. Took it to the dealer twice before the replaced both hubs. The hub had locked up with the 4x4 being half in and half out, resulting in busting the plastic ring on the back side of the hub. They also replaced the vacuum tubes and components thinking that would fix the issue, but the hubs were already busted. Also, did I mention that I have a 5.0, so they must have plenty of Torque to get the job done...LOL

 

Sounds familiar. My truck hasn't done it in a couple of weeks, but I'll be taking it in to the dealer with the complaint, anyway. What a PITA it is to have to leave it at the shop, get a ride home, and get a ride back to pick it up.

It hacks me off that Ford has known about this problem for 10 years and has not re-engineered it to cure the problem.

 

Just had my brand new Platinum in for a similar issue. Less than 4,000 miles on the truck. Long story short, the vacuum actuators were bad and were replaced under warranty.

Long story:

I was driving down the road at 70-75 MPH and started hearing a grinding noise. Pulled over and had the wife drive the truck in a tight circle while I stood in the middle of the circle attempting to determine where the sound was coming from. Determined it was the front hubs. Put the truck into 4A and grinding stopped. Back to 2H and grinding started again. Drive the rest of the trip in 4A. Took to the dealer when home and then "couldn't replicate the grinding noise". Told me to come pick up. I had it back the next morning and drove the shop foreman around the parking lot. He heard and they made the repairs.

The hubs work like this, they are actually disengaged by the vacuum. When you truck is parked and turned off the vacuum is released and the hub engage. When you start the motor vacuum disengaged the hub. Shifting into 4x4 cuts the vacuum and allows the hubs to engage. My actuators were bad, allowing the hub to engage while traveling down the road at 70 MPH and making one hell of a racket.

Annoying that it had to go in twice to get fixed.....also annoying that they haven't improved this system to something more reliable.

 

All very familiar. The second time this happened to my 2005, it was after I was cleaning my engine compartment and got a solenoid on the firewall wet. Once wet, the solenoid cannot send a strong enough vacuum signal to the locking hubs -- leaving them partially engaged.

The part that hacks me off is that Ford KNOWS this system is problematic (they use a different system on the HD trucks) and yet, they've used it since 2004 without any major re-engineering.

 

I have had a 4wd snapping issue since last summer. I recall power washing my engine bay in spring. I wonder if I caused this myself. Shoot...

Only way to find out is if I disassemble the front end and pull the actuator out and see if it leaks water. If not then I can only assume if the vac lines are good that the module is toast.

With the engine running/vac applied, the front left CV does not operate, but the pass side CV axle remains locked.

 

If one IWE is locking / unlocking normally, I'd say your solenoid it OK. The one IWE is probably bad. On the plus side, it's not all that difficult to replace one.

 

I've noticed, might just order one and replace it. Would it be a waste to replace the drivers side also? I just feel everything should be replaced in pairs/sets. I'll be ordering once I check my passenger side vacuum line.

 

If it were me, I'd replace both of them - for the same reason you mentioned. After all, they're not famous for lasting a long time anyway.

 

I had a grinding noise in my front end last year @ 59,000 miles on the 2012 and it turned out to be the front pinion bearings had gone out. I have no idea why, but I do use 4WD several times a week every week so they should have been well lubed.

 

There are days when I regret not buying a 4WD when I bought mine. It’s not something I would hardly ever use and threads like this make me glad I didn’t. I wonder if they are using the same system in the 15’s? One would think that after 10 years they could whip a vendor in shape to make a decent part.