Daelomin

Hey all, thanks in advance for any assistance you might lend. Disclaimer: I'm no mechanic but I'm pretty good a figuring things out and trying to fix things on my own to save some money when I can.

Here's a play-by-play of exactly everything I've done and what my current problem is.

I've got a 2007 F150 XLT and while driving into town one day a while back the truck just all of a sudden started vibrating so bad I thought it was going to fall apart. I pulled over as quickly as I could and after looking around a bit the problem was that the center bearing on the 2-part driveshaft had blown. Since the truck was in the middle of nowhere (I live a ways out of town) and I didn't want to have to pay for a tow, I thought to myself that I should just be able to drop the driveshaft, shift in to 4WD, and just limp the truck home where I could wait until I'm able to get a new driveshaft.

This plan didn't work out at first. I removed the driveshaft but when I went to engage 4WD it wouldn't go and all that would happen is I'd hear a kind of whizzing sound from somewhere in the front end. No matter what the front wheels wouldn't engage though and I couldn't move. I thought maybe the truck should've been shifted into 4WD to do what I was trying to do BEFORE I took the driveshaft off (maybe the driveshaft needs to be on to offer some kind of resistance in order to properly engage 4WD?). Anyway, with this thought in mind, I quickly put the busted driveshaft back on and then tried engaging 4WD again and this time it worked! Great, so I removed the driveshaft again and slowly drove the truck home in "front wheel drive".

After taking my driveshaft in to my trusted mechanic he informed me I needed a brand new driveshaft. He ordered it up for me and when it came in I brought it home. The truck had been sitting for about a month at this point so I started it up and moved it to a place where I could work on it.

Now, this may be my mistake... not being a mechanic I just don't know. However, after parking the truck to work on it, I DID NOT disengage 4WD.

I put the new driveshaft on and filled the transfer case with ATF. When I started up the truck, before moving anywhere I turned the dial to 2WD because I thought I should just test the 2WD first to see if it was working. Didn't notice any weird noises or anything and headed out onto the highway. Everything was working great, even at highway speed. I went down a side road to turn around and head back home, and while stopped at the stop sign sign before turning back onto the highway I turned the dial to 4WD to give it a test. I heard no noise, not even the usual small clunk that lets you know 4WD is engaging. I thought that was weird, but that maybe I had to be moving a bit for it to properly engage, so I pulled onto the highway and started heading down when I got a really nasty, hard CA-LUNK that felt really bad, followed by that familiar old whizzing sound I heard before when I had first removed the driveshaft and then tried to put it into 4WD. I quickly switched back into 2WD because I didn't want to hurt anything, but as I'm driving the rest of the way home even in 2WD this whizzing sound is going nuts.

I got it home and tried a bunch of stuff (putting in neutral, then shifting, going slow, etc) and every time I get this god-awful, hard, rough CLUNK whenever I try to engage 4WD followed by this whizzing sound.

I've had a lot of issues with this truck lately and thought I had gotten the worst of it fixed (exhaust manifold replaecment, power steering, etc) to the tune of about $5000 worth of repairs in the last 18 months, and I just can't afford anything else big right now. And yet, I need my truck. So here I am hoping someone can help me out with identifying the problem, and hopefully it's an easy fix.

Sorry for the wall of text, but hopefully I've described everything clearly enough to give a good picture of what's what.

Cheers

Martian

Sounds like either transfer case or front diff is toast

edit: Also, moved to 2004 - 2008 for higher visibility.

dyeguy1212

iTrader: (1)

Still trying to figure out this whizzing sound. Are you sure it's coming from under the truck? Is it mechanical or could it possibly be a vacuum leak that sounds goofy?


Have you ever had to repair your IWEs? What about the solenoid?

Daelomin

To my untrained ears, whizzing is definitely mechanical in nature, not some air/vacuum leak. To my knowledge the IWEs/solenoid have not been repaired, but I'm not sure about before I acquired the truck as I bought it used.

grss429

[QUOTE=Daelomin;4840069]To my untrained ears, whizzing is definitely mechanical in nature, not some air/vacuum leak. To my knowledge the IWEs/solenoid have not been repaired, but I'm not sure about before I acquired the truck


Maybe your IWE actautors are toast.. the hard clunks/wistle is them trying to engage rock auto has them both sides for 100 bucks.. also get the updated IWE solenoid with rain shield

Or it could be the miles u drove in 4wd.. btw future reference.. the halfshafts on our trucks dont spin unless its in 4wd.. so you would of been fine removing the cv axle and driving in 2wd.. cause they never were spinning

Daelomin

How would I go about diagnosing myself if the IWE actuators are toast?

Martian

The short method? Replace them. They're cheap.

Daelomin

I suppose, but "cheap" is a relative term, and why spend $200 on something if it turns out in the end that they're not the problem?

Martian

Okay... then start ACTUAL cheap and borrow a vacuum tester and test your vac lines. If they test good, consider the hubs and continue trying to find the sound.

Martian

Basically in 2wd with the engine running and the front two tires raised, if you spin the front tires, the CV shafts should not rotate. If they do, you either have a vacuum leak somewhere or your IWEs are dead.