F-150 Lifted on 37" Mud Grappler Pics, Question

[Josiah]

http://www.nomoreroominhell.com/Sandizzle/Josiah/lifted_4.jpg
I'll get better pictures when the tires are actually mounted. I installed the lift over the weekend and have a huge problem. My front driveshaft is clicking and clanking like crazy when it's installed, and it's spinning while in 2wd! The vacuum lines are connected to the hubs, it was fine before the lift. Any ideas what this could be? I can drive it fine with the front driveshaft out of the truck, which it is right now and it's getting rebalanced and keyed at a shop. Anyways, I'd really appreciate some help.

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2004 F-150 Supercrew Lariat 4x4
Fabtech 6" w/Coilovers
37x13.5xR20 Nitto Mud Grapplers
20x10 Mazzi Hulks
Dual 16" Derale Electric Fans
Air Force One Cold Air Intake
Custom Tuned XCal2
SIDO Flowmaster Single Chamber (formerly Magnaflow)
Underdrive Pulley's
Several Custom Mods (custom shifter, decal overlay, 4x4 emblem, etc)

[RawPower]

sometimes the spinning of the driveline goign through the transfer case spins the disenguaged part to. It wont spin nearly as fast, but you wouldnt be able to tell when you hop out and look under it... Or maybe your auto hubs have gone to shit, oh wait all auto hubs are shit... you should swap to manuals, better yet drive flanges... jk, but seriously, they could have broken. but thats not liikely if you know that they worked prior to the install.

Edit: nice tires, those are $$$

[saf-t scissors]

All the vacuum disconnect should do is detach one side from the other. The driveshaft will still spin, but at about half speed.

No autolocking hubs on that truck. The axles are splined right into the wheel hub.

[RawPower]

oh thats good, didnt know ford changed that...

I mean for a dedicated trail rig I like to have man hubs, but anyways... I dont deal with the newer trucks ever.

[Josiah]

Still have no fix, I've taken this to several forums I frequent and nobody is able to help. I dread taking it in to a shop, can install a lift but can't fix a snag.

[animator]

Spinning in 2wd is normal. Clicking and clanking may be due to it binding due to the increased angle. You would probably also feel some vibration along with it.

Or it may be as simple as a worn u-joint.


My suggestion is to leave the front driveshaft out. Most mall-crawlers leave theirs out, so it's ok if you do it too...

[Josiah]

I had a few buddies with 4wd F-150's to check if their driveshaft was spinning in 2wd and it wasn't.

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.
http://www.nomoreroominhell.com/Sandizzle/Josiah/vacuum diagram.jpg

[saf-t scissors]

I had a few buddies with 4wd F-150's to check if their driveshaft was spinning in 2wd and it wasn't.

How would they know? Had somebody crawl up under the truck while it was rolling down the freeway?

It's a VACUUM system. Which means it needs vacuum to work. If there's a leak, it doesn't work, and you ride around in 2wd. The air you hear getting pulled through the valve is probably coming in from the intake port that relieves vacuum in the system when it disengages.

Have you checked your driveshaft? Clearance, bind, u-joint condition?

[redranger4.0]

granted its not the same truck but when i put my IFS lift on my 00 ranger i had the same noises with my driveshaft. turned out the stock couldnt handle the change in angles. i had to buy an aftermarket/custom shaft for it.

[Josiah]

Saft, don't think too hard about it, it's pretty easy to do. I just did that myself this morning. I put it in drive knowing it does not have enough power to climb my driveway so I could push the wheels in order to accelerate up the hill. Not safe but it worked.

This is what I just did, and discovered the problem. It's a malfunctioning solenoid.

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. 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.

[BrokeCuzWheelin]

I have had several stock 04+ F-150's come in with the "hub grinding" complaint. All of them have just been a partially broken vacuum line that was allowing a vacuum leak. The axles on those truck are not splined directly to the hubs. The axles are disengaged from the wheel hub when vacuum is applied and the engage when there is no vacuum. Therefore, when there is a vacuum leak the hubs are only receiveing partial vacuum causing them to only partially engage which causes all the noise. Look all the lines over very closely, there is most likely a cracked line somewhere.

[Josiah]

I figured out the problem and have checked the lines. The lines are fine, the vacuum solenoid is out, it won't "couple" the two hoses when 4wd is disengaged. You are very right about the hubs needing vacuum to "disengage" rather than to engage them, it's the opposite on the F-150's so I'm glad we're on the same page. Maybe this will help diagnose other F-150's that come in with this problem, if you read the post right before yours I explain the problem/solution ;)