Ok I have a 05 F150SC FX4 with 65K, never had any issues with her until now. I'll be driving in a straight line say about 60mph and out of no where I'll get a loud grinding sound from the engine compartment area. Sounds EXACTLY like an exhaust pipe dragging on the pavement from inside the cab, like it fell off.

But thats not the case, I pull over, get out and look everything over and there is nothing visually standing out under the truck or the hood. This has happened twice now about 3-weeks apart?
As soon as I get back in and drive off, the noise is gone..................

The only thing that needs maintence is my brakes. I need to get new rotors and pads as when I bought my truck used @40K mi the dealership threw on new pads without resurfacing the rotors and now they have a bad "lip". My brakes dont stop like the used to so I have to get new rotors and pads and start over....could this be the noise I hear? Something loose?

 

update:

It happened again and its deff coming from the drivers side front wheel. I enguaged the 4-HI when the noise reappeared and I heard the 4x4 engauge with a normal "click, thunk" and the noise instantly went away. This happened again and I repeated the sequence and the noise stopped.

So it has to be the front drivers side hub right? For some reason in 2x4 its doing something to make a grinding sound. I dont know enough about 4x4 to diagnose but I know many here do. Whats the problem?

 

I was thinking a failing bearing assembly, but not sure why engaging 4x4 would "resolve" the issue. Unless it has to do with your auto locking hubs, it may be a vacuum issue occurring that could be part of the problem. Try looking at this thread: https://www.f150online.com/forums/su...ront-hubs.html

 

Fireman....I had the same exact situation happen with my 2001 SuperCrew and it turned out to be my hub assembly failing (it even did what you described when puting it into 4 wheel)...and it was critically close to having a major failure which could have proven dangerous in traffic so I say don't mess around and get it fixed. Not 100% sure that's your problem but you describe it identically.

 

2001 and 2005 are totally different. 2001 does not have a hub, it locks at the diff. It is probably the IWE going bad. Either that or a vacuum leak to the hub, or a bad solenoid.

 

Actually a 2001 and 2005 both do, I'm talking about the front wheel bearing/hub assembly....

 

Yes they both have hubs/bearings, but the setup is totally different. The 01 is nothing but a bearing, the 04 is a bearing and a locking hub. The IWE is notorious for these problems, whether bad or having a vacuum leak/bad solenoid. As the default position for the hubs is locked, any lose of vacuum will cause them to grind.

 

Any updatte on the fix? Mine has recently done this and I swore the truck was gridning metal hard. Not only was it scary to hear my truck make this noise, super embarassing too. Off to the shop today.

 

Update: I dont fequent the forum much anymore. sorry.

I had it fixed. It had 2 bad IWE's and my passenger hub assempbly was way out of spec. Got two new IWE's, new hub assembly, labor, etc =$689 OTD.

OUCH! But it runs/rides great. No more grinding or loud popping sounds when in 4wd off road.

 

Did the same on mine.. 2 hub / bearing assemblys and two cv axles and new front shocks.. Did the work myself and total $460.00.. Glad you got it fixed .. I was a little edgy about doing the work myself but its mor time consuming taking everything apart than replacing the actual parts..