Hello everyone. Long time reader of the forum, first time poster. I have gotten a tremendous amount of information from this site so I thought I would post an issue I am having with an '06 4WD (ESOF) 5.4L with 32k miles and see what kind of help you guys can offer.

A few weeks ago I had a problem with 4WD. 4WD light on dash would flash a few times every few minutes and when I tried to shift into 4WD while driving, sometimes 4WD would engage and sometimes it would not. When it would engage, I would hear a noticeable GRINDING noise as it shifted from 2WD into 4WD. The grinding would only last a second and then go away.

Took the truck to the dealership and the found out the shift motor in the transfer case and the IWE solenoid were bad. They replaced both. Flashing 4WD dash lights went away and the truck now shifts into 4WD every time. The problem I still have is the brief grinding when 4WD is engaged. Took the truck back to the dealership and they same the grinding noise is normal and is a result on everything synchronizing as 4WD is engaged.

I have had the truck since it was new for 2 years and put 32k miles on it. I use 4WD a couple times a month but no serious off roading. I have never had the grinding issue before. Now that I have it the dealership says it is normal and I have trouble accepting that.

I have read a lot on this forum about problems with a constant grinding noise (often describe as ice in a blender) in 2WD that is attributed to the IWE and IWE solenoid. In that situation, the IWE are partially engaging. From what I have read, my issue is different in that my truck only grinds momentarily and only when shifting from 2WD to 4WD while driving over 5mph. My IWEs are engaging and disenaging, they just make a grinding when while engaging.

I am pretty sure the grinding noise is coming from the IWE because I have done a quick test of their operation myself. I have disconnected the vacuum lines to the IWE solenoid to bleed off pressure to the IWE vacuum actuated shift mechanism. I also capped the vacuum from the IWE solenoid so the truck does not see a vacuum leak. From my understanding of the Ford 4WD system, the result of no vacuum at the IWE shift mechanism will result in the IWE being locked or engaged ALL the time, whether the truck is in 2WD or 4WD. A test drive in this configuration results in no grinding at all when shifting into 4WD. Just normal noises from the transfer case (a little clunking, clicking of solenoids, and such). But the grinding noise is gone. Pull over to the side of the road, reconnect the vacuum line to the IWE solenoid, and the grind returns.

I also looked up some information in the Ford DVD service manual (section 308-07A-4). In one of the trouble shooting tables it had a symptom listed: "Grinding noise during 4WD engagement, especially at high speeds." This symptom describes my issue exactly. The service manual lists the possible source as: "Front halfshaft speeds not turning at the same speed." The service manual action is: "INSTALL the S-spring in the front differential. Refer to Section 205-03 for the S-Spring installation." I could not find anything more about this referenced "S-Spring". I could not find any reference to the spring in section 205-03 or anywhere else.

I printed out the page from the service manual and showed it to the dealership today. They do not see the connection.

Am I being too picky here or do I indeed still have a problem? I know the truck has to do a lot of things when engaging the transfer case and a second axle. Noise is normal, but not grinding.

Sorry for the long post, but just trying to give everyone an accurate description of my problem. Any ideas would be appreciated.

 

Take it to another dealership. I don't have a 4x4 so I really don't read up on transfer case issues. If the first dealership is trying to just brush you off, go to another one. If it isn't supposed to act like that, then they'll tell you.

 

s27payne, you get anywhere with this? Update?

 

Jimbo45,

Sorry to say no updates on my end. Still have the problem a couple of months and a couple of thousand miles after going to the dealership.

My problem/noise is definitely coming from the Integrated Wheel Ends (IWE) (i.e. the wheel hub). I now that because I bypassed the IWE solenoid and and had the IWE constantly engaged while going for a test drive. With the IWE constantly engaged, shifting into and out of 4WD is seamless and no lite grinding. Hook up the IWE solenoid to let the truck engage/disengage the IWE as it needs to ..... and the lite grinding returns.

Regarding the S-spring.....I have a Ford DVD shop manual and can not find anything about the S-Spring so I am not even sure what it does or how to install on the F-150. Not even sure if it replaces an existing part or adds a new part. I showed the TSB (on the explorer or expedition, I think) I found online about the S-spring to my dealership, they did not even look at it. Very frustrating. When the weather warms up, I will look into the S-spring a little more aggressively.

Even more frustrating is the truck shifted into and out of 4WD beautifully and quietly for the first 30k miles, now it starts making an unusual noise, and they say it is normal.

I will keep in touch and let you know what comes out of the S-spring when I can look into it more (or anything else I find out).

Steve

 

Testing this way will not allow the IWE to do anything but stay where it is, engaged. You can still engage and disengage the transfer case but the IWE will always stay locked. So by doing it this way, it WON'T make the noise. The only noise you might hear is just the TC and everything taking acting. I would say your noise is an IWE not fully engaging when you switch to 4WD, the opposite of the typical problem. It's pulling back when you start the truck, but when the switch cuts the vacuum it partially engages and grinds. I would take a guess and say the noise is the other side's IWE.

I will check my shop manuals and see if I see anything regarding this s-spring. And regarding the dealer, they don't like customers who are informed. That keeps them honest. They would rather have them dumb and uniformed so they don't have to really tell them anything about a repair, they can BS and the customer would not know any difference.

Mine was fine for the 10,000 miles since I bought it then out of the blue, I'm having this problem and with both sides. My father-in-law has a 2004 with 40k and has NEVER had this problem. It's very odd...

 

I have this same engagement noise as payne does. 4wd works as it should, and engages quickly enough, but it just started making noise as it engages. The noise is a brief whir or scrape, then ends in a clang. Some might call it a grind, but that seems to be a strong word for my noise. Keep in mind, the noise is subtle, and with the HVAC or radio up, or on a bumpy road, may not even be heard. It occurrs mostly when temps are below freezing, and about 90% of the time 4wd is engaged. It is just bothersome, though, because it used to engage very quietly.

I think the "s" spring TSB has some merit. I don't know exactly what an "s" spring is, or where they go on the front diff, but the mention of "CV shafts turning at different speeds", seems to make sense to me, and my noise. Say, after the T case shifts into 4wd, and starts to spin the diff, if for some reason, the right shaft spins twice as fast as the left (very possible with an open diff), then I can imagine some grinding or noise would be heard when the IWE's hook up with shafts turning the wrong speeds than the wheels. If both shafts run at the same speed when the IWE's hit, then the engagement would be much smoother. If for some reason, the diff is not turning the shafts at the same rate (maybe higher friction or turning resistance, on one side than the other), then I can't see how there wouldn't be any noise when the IWE's engage.

The question is, why are the shafts turning at different rates, and how can you fix it? Maybe this "s" spring is an added part in the diff, that acts as a temporary locker or somewhat of an LS (limited slip), in light torque situations, that keeps the shafts at the same speed upon engagement. Someone with experience with this "s" spring needs to chime in.....

 

[QUOTE=TN-F150;3545424]Testing this way will not allow the IWE to do anything but stay where it is, engaged. You can still engage and disengage the transfer case but the IWE will always stay locked. So by doing it this way, it WON'T make the noise.....
QUOTE]

Thanks TN-F150, you are exactly correct. I made a typo in my post. Meant to say "no lite grinding" but fat finger typed "now lite grinding". Manually over-riding the IWE solenoid by disconnecting it does make the noise go away completely.

Appreciate what you might be able to share about the S-spring.


Payne

 

Yeah, I got a few of those.

I will check my books tonight and see if I see anything different on paper than you did on CD.

 

Interesting...mine is almost silent when engaging and the noise is in 2WD only.

This makes sense...While I had mine up in the air and testing the IWE's, I did notice that one side (half shafts) did spin at different a rate than the other both while engaging and while engaged depending on which one had the least resistance. I'm guessing this "S spring" balances the torque and allows them both to spin close to the same speed, as you mentioned. I'll see if I can find out WHERE it goes.

 

Hey, here is the referenced TSB regarding the s-spring.

http://fcsdchemicalsandlubricants.co...r/tsb/0364.pdf

The tsb is for a 2003 Expedition/Navigator and the problem is different from what this thread is talking about. However, the root cause is the same, half shafts turning at different speeds.

Another post on this forum (could not find it this morning) having 4WD problems referenced this tsb as addressing the "different half shaft issue" and it cured his problem.

 

Ok, a little update. A week or so after posting about this, I took my truck in to the dealer. They replaced the IWE solenoid, and apparently didn't test drive it, because, as I expected, the solenoid was not the problem.

I didn't worry too much about it, and needed my truck everyday for several weeks, and put the noise on the back burner. I figured I would call them sometime before the warranty was up, and have them look at it again.

Well, out of the blue, I checked my paper work on the warranty start date, since I am almost at 34,000 miles, and low and behold, TODAY WAS THE LAST DAY UNDER WARRANTY!!!!! OH NO!

So, I franticly called the dealership, and after some calling back and forth with my saleswoman, a nearby Ford dealership said if I could get it to them today, they would submit a work order, and it would be covered under warranty. Fingers crossed here.

Again, to recap, here is what the problem is, nearly identical to Payne's (the OP). 30,000+ miles, 2006 4x4, purchased used. No grinding when in 2wd. When shifting into 4wd and rolling, a brief and nerve rattling whir/grind/clank can be heard as the hubs engage. 4wd works as it should after engaing. I can produce the noise by rollling 20-25 mph, and turning the **** to 4H (I am afraid of damaging something, if engaging it at a higher speed).

When I got to the dealership, they had a tech, that seemed very knowledgeable about the 4x4 systems ride along with me so I could demonstrate the problem. After hearing it, he said he believed one of the IWE's or hubs to be damaged, and said it needed to be fixed. I also discussed with him, the "S" spring, and differing shaft speeds as a possible fix/problem. He quickly replied with "Well, the "S" spring is something we do on the Expeditions with this problem, but this has a different system". I was impressed with this guy, and he has shed some light on this "S" spring mystery.

Hopefully, there is a fix, since the "S" spring appears to not be an option with our F150s. I will post what they come up with, when I am notified, and or it gets repaired.

 

No call from the dealership yet....I hope thats not a bad sign. Its scarey to think that it is officially out of warranty as of today. Anyone else with this problem? Surely someone besides me and the OP, s27payne, have had this issue. Anyone?

 

Called the service department today, and they said its fixed, I will pick it up tomorrow, to find out. I asked what was done to fix it, and the manager said they put another new IWE solenoid on it again!? He said there are at least three part numbers, and new versions of the solenoid. They tested the one that they just put on in January, and said it was bad. Now it has an even later design solenoid. He also said that they inspected the hubs for moisture, and found none. I assume (and hope) they looked for hub damage while they had it apart. I am not convinced that this will actually fix the grind as 4wd engages, since it never had any grinding in 2wd, which according to what I have read, is a tell tale symptom of a bad solenoid. I still suspect the grind is due to the halfshafts spinning at different rates. But I guess I will find out if its fixed tomorrow morning. If not, I am probably screwed, now that my warranty is up.

 

Having had very similar problems to yours - and having replaced both IWEs and the soleniod on my truck - I kind ouf doubt that you're in the clear yet. If the solenoid goes bad and doesn't do it's job correctly, you may partially engage your IWEs - which leads to that grinding sound. So, if you replace the solenoid, you fix one part of the problem, but the damage to your IWE's may already have been done.

Don't worry if you still have a problem though. You brought the truck in for repairs while to was still under warranty. So, if you still have a problem, they have to fix it under warranty. Just make sure the problem is totally fixed before you let them off the hook. My guess is that you might still need an IWE or two.

Another thing you might want to think about. Even if the problem comes back, the replacement of any of the parts I mentioned isn't all that hard. I'd never done this job before and with the instructions TN F150 provided, a buddy and I did the entire job (2 IWEs and the solenoid) in about an hour and I think the parts were something like $180.00. It's a crummy system, but at least it's easy to work on.

 

2stroked, you are correct. You got two IWE's and a solenoid for $180???? Ford parts?

***Update!!!!

I picked up my truck fist thing this morning. Noted on the service sheet was sloenoid replacement and IWE vaccuum systems inspection for mositure.

Drove it off the dealer's lot, and when rolling about 25 mph, I engaged 4wd. Still made the irritating noise, with no change. I tried it a couple more times, and took it straight back to the dealer. My hopes that it could be fixed were all but gone.

I told them it wasn't fixed, and they had another mechanic ride with me to demonstrate the noise again. I did so, and this very polite, but young, tech started to explain to me that the noise wasn't a problem. I politely explained to him that I did have a little knowledge about how the system worked, and I knew that other trucks did not make this sound, and I don't wan't something to fail as a result of this, down the road.

He accepted my position on the matter, and he told the manager that he felt there may be unaddressed problems, and after the manager talked to the head master tech, they said they would work on it today, and see what they could find. They apologized that I had brought it twice already, with no success, and explained that they simply started with the common repair (replace solenoid) for 99% of "2004-2008 4x4 grind" jobs they see. They even offered me a loaner, but I declined, since they felt they would fix it today.

Called them back at the end of the work day today, and they had just finished it. It was still covered under warranty, since the fix that was initiated under warranty, didn't solve the issue. The master tech explained that they replaced both vaccuum IWE's, and that they successfully test drove it.

Driving it from the lot, I tested it. YAY!!!! No more whir/grind/clang when 4x4 engages! Even if I have all the windows up, radio and HVAC off, and on a smooth road, I can just barely hear and 'feel' it go into 4wd, and this is how I recall it being. I'm thrilled, and super pleased with my dealer. There is a reason that this dealer does so well, and has earned my last 3 purchases! Thanks!