This thread is hopefully what I needed. I can hear "the noise", starting to sound more and more like grinding. I have a 2007 5.4L 4x4 Screw with less than 67,000 miles and it only recently started. From the inside of my truck it's not easy to stick my head out of the window and hear where it's coming from but tonight, I was able to get a really good notice of this grinding. It's coming from the front, probably one of the hubs. After reading up on all of this, I feel confident I'm having the same issue. At first it wasn't so much a grinding sound as it seemed more like wind noise. And with my safari rack, I had my doubts. In fact, the earlier sounds I've been hearing made me doubt any sort of metallic grinding was happening in the first place.

The grinding happens most when I'm making a relatively quick, tight left hand turn, going at 40mph or higher, or accelerating from a dead stop at WOT. However, it totally goes away when I let off the throttle, I assume this is due to a drastic change in vacuum pressure?

My wife is going to take my truck in today since I have to work early and my baby is my daily driver/work vehicle/family truckster. I will have her suggest a vacuum issue, and hopefully they will follow in on it. I will inform as soon as I hear anything.

 

As most of you i have the same problem I have replaced solenoid and actuator on driver side yet the problem persist. I'm going g to test my vacuum lines next. I have a great video of the sound I'm having if I am able to post it I will. But if any mechanics out there could give me pointers I can send them the video. Or you can email me to send you the video. I have an 06 f150 5.4 fx4

 

My 2008 has the same problem but when it happens my instrument cluster and radio lose power.... Anyone else have this problem??

 

You might want to check the vacuum lines above the hubs, where they come up and go to the other hub. They'll be wrapped in heat tape and flex tubing. I had a tiny crack in the line and that was the cause of the grinding. The grinding sound stopped when I went into 4WD, but came right back when I went to 2WD. I intend on replacing all the vacuum hoses for the 4WD system. They're thin and very brittle.

 

I have a 2004, and my solenoid is on the passenger side right where water from the trough below the windshield cascades down over the fire wall. Horrific design. The new solenoid comes with a little deflector hood, which was not supplied with the original.

 

Just wanted to say thanks to all those who provided on this thread. I was able to diagnose my problem and get it fixed with a little piece of hose. My symptoms were when doing a hard acceleration or any acceleration uphill I would here a light crackle sound almost like the blender in ice sound. It would go away if shifted into 4wd HI. I removed the vacuum tube from the iwe solenoid and drove it a short distance and it was fine. I then discovered a break in the small vacuum tube just past the elbow. This was causing the hub to try to engage during acceleration and making the sound. With the engine running I could hear the air leaking out of the hose. Repaired the hose and all is well. I hope I did not do any major damage to the actuator or the hub but appears to be working fine.
Thanks again to all the posts.

 

( I RECENTLY HAD THE SAME ISSUE. I HEARD SOMETHING LIKE A BLENDER CHOPPING UP ICE & THOUGHT IT WAS EITHER A WHEEL BEARING/HUB ASSEMBLY OR A CV. I CHECKED FOR BOTH AND DIDN'T THINK IT WAS EITHER.
SO I TOOK THE VACUUM LINES OFF & UNPLUGGED THE SOLENOID (VACUUM PUMP) AND NOTICED DOWN ON THE NIPPLE OF THE VACUUM CONNECTED TO THE HUB WAS ENTIRELY FULL OF RUST & SO WAS THE SOLENOID (VACUUM PUMP) SO I TOOK A NEEDLE AND A SHOP VAC & CLEANED BOTH SIDES & BEHOLD! IT WAS FIXED. NO MORE PROBLEM.

SO TO ANYONE, BEFORE YOU SPEND OUT THE WAZOO FOR A HUB ASSEMBLY OR A CV JOINT MAKE SURE YOUR VACUUM LINES AREN'T FULL OF RUST. IT JUST MAY SAVE YOU AN ARM & A LEG.

SO IN REGARDS TO THIS POST I 2ND THE MOTION....

 

Just joined the failed IWE solenoid club. Thanks for posting all of this helpful info.

2005 Super Crew FX4 with 150,000 miles. Just had the horrific grinding noise happen yesterday. I literally thought I was dragging something or some part had grenaded under the truck.

No change in sound until I came to a complete stop. I also felt & heard the clunks as the actuator went back to normal.

 

I had issues with my 2004 F 150 this yr not locking in. Hubs good IWE good no leaks or ripped seals. My problem was that the teeth on locking ring gear wasn' meshing together. If this is what yours is doing I got the fix. Look at the axle where it goes into the ring gear and if you look good enough or you been grinding then this is how to fix the issue. My axle had some wear marks or lets' say a chamfer dubbed on the axle spline. I took a dremel and ground that flat had to take off .010-.015 then put a slight 1° angle leaving the teeth end sharp and bottom of teeth where its flat i put a taper of about 1° so it would grab teeth before anything else. Took me a couple hrs but it locks in now and not popping out on load or take off. Its harden high speed steel so dont attemp if you cant handle this technique on your own. I'm a retired tool maker . O.D. I.D GRINDER. MANUAL GROUND FOR 28+yrs. Best way to tell if it' rounded off on teeth is take and spray brake cleaner wipe it real good and take a marker Blue is more visable and color all way around the teeth and get a good metal file and swipe it flat a couple times on one half and where you see the marker is obvious low spots from grinding on locking collar of IWE. Keep color on so you know where you grind is. I hope this works for anyone having this issue of popping out of 4x4 on a 2004 F-150. Fix it instead of buying new one.