2004 F-150 Supercrew Lariat 5.4L 4x4 auto with turndial 4x4 selector.

Saturday during the snow, My wife went out to do some errands and needed 4x4. She turned the 4x4 selector to 4 low by accident but did not realize it. She drove 4 miles before the truck made a knock noise and jerked and the "failsafe mode" light came on in the dash. She then notices that the 4 low light was on. She couldn't get it out of 4 low, and had to call me to figure out how to get it out.

After getting it our of 4 low, and pushing "reset" on the information display, she went on her merry way with the failsafe light now off. After getting to Manchester about 12 miles away, and seeing the roads were just wet, she took it out of 4 hi and into 2 hi. After doing that, the truck made a noise like she was draggin a tin can. She noticed that it didn't make the noise in 4 hi.

She came home in 4 hi and parked it. I took it for a ride the other night, and it didn't make the noise. I drove it tonight and the noise came back. I realized the it only makes the noise in 2 hi, when accelerating. Let off the gas, no more noise. And again, it does not happen in 4 hi. Turn the selector to 4 hi on the fly, and it goes away immediately.

I jacked the truck up and started it, still in 4x4 hi, noticed that both hubs were locked to their respective halfshafts. I then took it out, but only the right hub released, the left stayed engaged. I changed the IWE Solenoid, and looked for water in the lines, but found none. I took it for a ride and it still makes the noise. It basically sounds like a shattered diff, it's really loud, and you can feel the noise in the floorboards.

Anyone know the next steps in the TSB report, or am I off to the dealer?

 

Sounds like that IWE is shot.

 

Which one? The left one? For some reason it sounds like it is coming from the right side of the truck.

 

Don't tell ATOM about this.
He is sure that the 4x4 systems on these are bulletproof!

 

The one that is making noise. It should not make noise in 2wd.

 

Should the hub disengage form the halfshaft when in 2wd? the right one does, the left does not. I don't know which one is making the noise.

 

When in 2wd, engine ON, the hub should disengage. If engine off, the default is engaged, no matter what position the switch is in. If the right front (from the drivers seat) is making noise while in 2wd, then it is bad, or vacuum is not getting to the IWE to disengage the hub.

 

Like I said the default is to be ENGAGED...So when you have the truck in 4x2 the hubs are supposed to release..They get the power to release through vacuum produced by the truck..So it sounds like the left hub is not working correctly if it is staying locked or there is no vacuum getting to the hub..

I can give you the whole troubleshooting instructions if ya want them..


I hope someone else here can give you some insight that has had this problem and fixed it..


Check other power train or 2004 and up..theres a ton of threads on the same stuff..