I just lifted my truck this weekend, 6" Fabtech w/Coilovers. I am stuffing 37's on 20's come monday, the rims were the Chevy 6 lug, not Ford 6 lug which is the reason I'm waiting until Monday for the correct ones to come in. On top of that problem, my front driveshaft spins while in 2wd. I have a 2004 F-150 and it's not supposed to be spinning. I get a horrible clanking and grinding in my front end somewhere, the vacuum hoses are both connected. I have gone to several forums I frequent and nobody is able to really help. I can drive ok with the front driveshaft off, and I'm doing so right now. It's in the shop getting rebalanced and keyed, I really hope there is someone out there who reads this and knows how to fix it so I don't have to take it in to a shop. This should be cake compared to the lift install.

 

New update: I went to Autozone, rented a vacuum gauge/pump. You pump air into the vacuum lines and I tried to crimp it in increments of a few inches on each hose until I got passed the hole. There was no hole that I could find. But I found the problem, it's right at the vacuum in the upper left hand corner of the trucks engine bay. The vacuum is attached to the firewall on the top left corner in the engine bay. I am wondering if that is normal for the air to come out of there while the engine is off, there is no way I can hear it while the engine is on but I can clearly hear the air escaping out of the actual pump with it off. Maybe the hoses are not attached to the pump well (maybe I pulled them out when stretching the hoses), I can't see very well but I have pictures below so in the morning I'll work on it. I am posting this in case any of you want to add anything or suggest anything at all.

 

I really have no idea, hope someone chimes in...c'mon people, ANYthing helps..even if you only answer part of the question, or give suggestions...I'm sure the man will take it at this point.
Good luck

 

So your in 4x4 all the time, or are your hubs not locking? -Meaning it is just your driveshaft is moving...

 

My driveshaft is spinning, so my hubs.

 

I suspect that you somehow damaged the vacuum lines or misrouted them or didn't properly reconnect them. Go over them inch by inch. You also could have damaged the hub assy when transfering it to the new steering knuckle in your kit.

JMC

 

I don't really know what the problem could be, but here are a couple of observations that might help.

First, unlike '97 to '03 F150s, you actually do have a type of locking/unlocking hub called the Integrated Wheel End (IWE) disconnect. It is a fancy vacuum operated type of disconnect at the front wheels. The '97 to '03s used a Center Axle Disconnect (CAD), which does not lock/unlock at the wheel.

Now, I think I have read that the IWE defaults to a hub-locked state when the ignition and engine are off. I would guess that when you crank up, vacuum is applied to the hubs to pull them to an unlocked state for 2wd operation. I would further guess that when you shift/switch to 4wd, or turn the engine off, the vacuum is removed, allowing the hubs to revert back to a locked state.

This is probably not much help and may be information you already knew. Since I have an '01 2wd, its the best I can do.

 

Problem Found:
This is what I just did, and discovered the problem. It's a malfunctioning solenoid, check my finding for me please. And for the record, the truck needs to be running for vacuum pressure.

There are 2 valves/tubes coming into the Solenoid, the bottom one is for the hubs and the top is from the "vacuum source". It sucks constantly about 22lbs of pressure and is pretty audible when disconnected. I believe the solenoid engages or disengages the top valves flow to the bottom valve, and thats where lies the problem. If I pump air into the bottom tube it disengages the hubs, I've jammed a pencil in there as a temporary fix and will be remounting my front driveshaft today when I pick it up ($56 to have it keyed and rebalanced at a nice shop). I should be fine with a new solenoid, pressure in the lines is being kept (but I did find a loose connection in one of the lines, not sure how recent it was made). Anyways, I do not know how a solenoid could have gone bad at the most innopportune time but I should have it fixed as soon as someone can get me a part number for this. I'm looking so I may find one soon. I also will be ordering the harley taillights if they're $30/each or for pair like they used to be. If there is something I wasn't very clear about let me know, I want this to be a good reference source for searchers in the future. I think the solenoid will be a cheap fix.

 

Glad you found the problem, Josiah. I know it isn't too uncommon for the '97-'03s to have a solenoid or vacuum lines go bad. In my old '97, they did. How much did you pay for your new solenoid? If I remember correctly, I paid just about $25.00 but that was on a '97 and you have a '04. Just wondering.

I do like the wheels you got on it though.

 

First, as SM mentioned, the IWEs default to the locked/engaged position when there is NO vacuum on the system. They use vacuum to DISENGAGE the hubs. Makes them fail-safe, unlike the 97-03 that will fail in the disengaged position, leaving you stuck when you need the 4wd the most.

Second, no matter what the vacuum gauge may be reading, it's not physically possible to pull more than 14.7 psi of vacuum anywhere above sea level.

Third, the vacuum solenoid was certainly your problem. However, jamming a pencil in the tube that runs to the IWEs won't keep them disengaged. Eventually the vacuum will leak down and the IWEs will re-engage. As a temporary fix, bypass the solenoid all together by plugging the vacuum hose from the manifold directly into the hose connected to the IWEs. Then, anytime the engine is running, the IWEs will be unlocked. To use the 4wd, pop the hood, disconnect the vacuum lines from each other, and plug the vacuum line that runs to the manifold to stop the leak. It's nowhere near as convenient as shifting on the fly, but it'll work.

Finally, running with the front axle turning doesn't necessitate the removal of the driveshaft. Many vehicles run that way normally (for example, the Explorers or Expeditions). Sure, it may cost you an MPG or two, but it's not going to hurt anything as long as the transfer case is disconnected.

Of course, the best fix is to repalace your vacuum solenoid, which I'm sure you're working on.

-Joe

 

I paid $52 at the stealership. I'm going to go take it off and see if I can fix it myself, that way I can cancel my $52 part I ordered

GiJoe, great recommendations and I dig the idea, thats what I'm going to be doing.