I have been having grinding issues with the front hubs on my FX4 when it is really cold out, 26F or below. I haven't had the problem when it is warmer out. I put the truck up on jacks and turned the front wheels (while truck running and in 2wd). Both IWE's are released and the half shafts stay put. Putting it in 4x4 locks both IWEs, and the halfshafts turn. I have already replaced the solenoid a few weeks back, and it was still making the noise. I checked the vacuum in the lines, all hold vacuum with no problem. Also, both hubs hold vacuum fine, absolutly no leaks. I also had a vacuum gause in the truck for the last few weeks (in the lines to the hubs), and it never looses vacuum when it begins to make the grinding noise. So, what the heck is wrong? I am wondering about freezing water in the IWEs. I always wash under the fenders and inside the wheels and really flood the front end since the salt it so bad here. Could the water have worked its way into the hub, and when it gets really cold out, freeze and bind the hub up enough that the vacuum can't pull it all the way apart? I have head the noise come from both sides. Could both IWE's be bad at approx the same time (started with the left, then onto the right, now back and forth)? Are the rebuildable, or sould I just order the $80 part from Ford? Thanks all!

 

The chance of both IWEs going bad at exactly the same time is extremely unlikely.

The ice theory is a rather good one, but you would be able to simply check the vacuum lines for moisture (at least I would think).

You bought a Ford... You didn't actually expect to drive it in ALL conditions, did you? Sorry, I know I'm not helping. I just had to pay to have my own passenger side IWE replaced, so I'm still a little hot under the collar with Ford (especially considering the whole 15k miles I got out of the first hub) .

 

Interesting.

I've got a problem with my 2004 FX4 spontaneously popping in and out of 4WD, but only partially; just enough so there's alot of grinding from the front end.

Then I just noticed something last night.

I can just touch the 4wd selector **** and the problem straightens itself out. The point being don't rule out a problem with the switch.

-fatz

 

I've also heard that the switch can be faulty as well.

 

Good point about the switch. But, I never lost vacuum when it makes the grinding, so I know (at least I think) that the truck never told the front hubs to engage. Even it the switch WAS bad and started to engage the transfer case or something else, it souldn't grind from the hubs since they would both be open. I know the noise came from the front end, not under the truck (transfer case).

 

When you say it pops in and out of 4x4, does the light on the dash come on? I would think that if the switch was bad the system would engage itself on its own, just like if you manually did it. Even if it was in and out, why the grinding? Just a thought.