Hi, I have a 2006 FX4 supercab. My initial problem was the shift on the fly for the 4X4. when I would shift on the fly there would be this awful grinding noise. When I shifted while parked there was no noise but the 4x4 didn't seem to engage properly.

I took it to a mechanic "friend of a friend" who replaced both integrated wheel ends at a cost of $300 to me. He thought this was the problem. Turns out that the grinding is still there when shifting on the fly.

HOWEVER. He claims that changing the wheel ends -hub lock has fixed the 4X4 so that I can shift while parked and the 4X4 will engage properly. (no snow, cant test yet)

So with that said... He says he got a diagnostics and that he believes that there is a problem with the 4X4 control module.

has anyone had any experiences with this?

Any help would be greatly appreciated.

 

Do a search on "IWE" here and you'll find tons of information on your problem. My guess would be that you had a bad solenoid (very common problem) that took out the IWE's. Replacing the IWE's, but not replacing the solenoid will take out a brand new set of IWE's in very short order. Look for a post by TNF150 for the most complete information. One of his posts even includes a couple of .pdf files from Ford on how to diagnose the common problems with the system.

 

What an incredible post from TNF-150 https://www.f150online.com/forums/20...replacing.html

Now I know what the IWE is...lol Integrated wheel ends.

Theres lots of reference to the solenoid causing the IWE's to grind and fail. Has anyone replaced the solenoid?

 

I'm stumped. Most ppl that have this problem state that the grinding starts in 2wheel and is stopped by switching to 4high.

Mine is the complete opposite, my starts to grind ONLY if I shift 4X4 on.

I checked my solenoid and its definately the old one. Doesn't have the lid over it. Can the solenoid cause the reverse to happen as well?

 

Yes, and yes. The solenoid is an easy replacement and a fairly cheap part, about $25 from the dealer (dealer only part). It takes about 10-20 minutes depending on how big your hands are, and takes a 10mm socket or wrench.

Do some reading on this and other forums and you'll see the 4x4/IWE system isn't too complicated or hard to repair.

If the solenoid is bad, or if moisture or debris get in the related vacuum lines, or there is a leak in the vacuum system/lines for the 4x4 system you could get grinding. It is possible other parts could be at fault though. The solenoid is where most people start because it's a known weak spot and is the cheapest part.

Read through these...;

https://www.f150online.com/forums/20...replacing.html

http://www.ford-trucks.com/forums/83...then-some.html

 

That's how my adventure started. Generally speaking, replacing both IWE's and the Solenoid will do the trick. If your solenoid was the original cause of your IWE's going out though - and you didn't replace it - you're probably looking at replacing one or more IWE's again. The solenoid is pretty cheap and quite easy to replace. I even have a spare sitting on the shelf now.

 

As mentioned above.............the problem 'could' very likely be fixed by simply replacing the solenoid which is very simple.

Under normal 2wd operation........you should have about 15-20 psi vacuum at the actuators/IWEs. When you switch to 4WD your vacuum is essentially cut to 0 psi at the actuators/IWEs.

Since your 2wd appears to be normal...........when you switch to 4WD your solenoid is probably not operating properly and not sufficently reducing/eliminating the vacuum at the actuators

With a vacuum gauge about 5 min ..........you could check to verify what the vacuum is doing.
(Before you start you should have the vehicle in park, the parking brake on, and all 4 wheels chocked )
1) Check one wheel at a time. Simply remove the vacuum line at the actuator (just pull it off the connetor on the actuator) and use an adaptor to insert the vacuum gauge.
2) Start the engine and you should be measuring about 15-20psi vacuum
3) Now with the engine running.....switch to 4WD. You should now see about 0psi vacuum.

Chances are.............you will not see your vacuum go to 0psi if you are having solenoid issues.

4) Now.....change the solenoid. Repeat steps 1-3 above to verify that your problem is resolved before you grind any more hub/actuator gears

Hope this helps!!!

 

I stole this from XJCamaro and edited/added stuff I stole from other people on other furums. I printed it and stuck it in my crappy Haynes manual.

Everything You Wanted To Know About The IWE System...And Then Some

This is all being said assuming your shift motor on the side of the transfer case is working properly.

When the engine is started and running, vacuum is exerted through a solenoid to the IWE/4x4 system. When the engine is turned off or 4WD is engaged (either by floor shifter of dial selector) vacuum is released by the IWE solenoid to the actuators at the wheels. Vacuum to the actuators at the wheel unlocks the hubs for 2WD and release of vacuum by the solenoid locks them for 4WD. A vacuum leak at any part of the system, or solenoid malfunction, can cause failure.

The vacuum builds when the engine is started. The vacuum (from the intake manifold on 4.6L) via a vacuum line exerts vacuum on the entire IWE system all the way to the actuators. There are two check valves and a vacuum box/reservoir that regulate a constant vacuum pressure in the system. The first check valve locks the vacuum at the highest vacuum that is exerted from the engine from that check valve down. The vacuum box/reservoir holds that highest vacuum exerted. The second check valve located right before the IWE solenoid holds the highest vacuum to the actuators from what has been exerted from the engine.

As you start to understand the vacuum system, you will see that the vacuum box that is located between the two check valves does in fact act as a reservoir. When you engage the 4WD, vacuum is released by the solenoid and locks the line from draining back. This process allows the lines and vacuum box between the two check valves to hold the current highest vacuum even though the engine vacuum is constantly changing and the vacuum from the second check valve to the actuators has been lost. When 4WD is disengaged, the solenoid is opened back up, the vacuum reserve from the vacuum box is then used to exert vacuum on the lines to the actuators, unlocking the actuators no matter what the vacuum from the engine is. The vacuum box/reservoir maintains a constant vacuum pressure as long as the engine is running.

If you try to shift into/out of 4WD and it will not engage or disengage, it’s possible your solenoid is not working and releasing the vacuum to the actuators and engaging the hubs. This might happen because of the early design of the IWE solenoid lets water run from the cowl onto the top of the solenoid causing damage. The new style solenoids have a shroud on them to prevent this. Replace the solenoid (Ford only part).

After saying all of that and you think about what the manual says about turning the 4WD on and off, you notice that you are supposed to activate and deactivate the 4WD while under a certain speed and not while accelerating. This ensures two things. First, high speed engaging and disengaging of the gears in the hubs which can cause mechanical damage does not happen. Second, it allows a quick window of no load and low RPMs from the engine, providing high vacuum from the engine, which will quickly replenish the high vacuum to the entire system and “locks” that vacuum between the two check valves and reservoir box, as well as from the second check valve to the actuators. This, when working correctly without any leaks ensures a high enough vacuum to keep the actuators unlocked when you’re in 2WD, or unlocking quickly when shifting from 4WD to 2WD.

A leak in one of the lines, the reserve box, an actuator, or a faulty check valve(s) can allow a leak in the system that will allow the actuators to possibly try to engage or partially engage while driving. If you hear a grinding or whining of gears at certain speeds or loads you may have leak in your IWE vacuum system, allowing the vacuum to drop to or below the 5 lbs of vacuum needed to keep the actuators unlocked. That is the grinding or whining noise of the gears/actuators trying to mesh together. Some say it sounds like ice in a blender or sheet metal being dragged under the front of the vehicle.


To test the vacuum system, get a good vacuum pump with a gauge on it, about $60 (or cheaper) at a lot of parts stores.

Troubleshooting:

1. If you can put the truck on jack-stands, you’ll be better able to check for engagement/disengagement of the actuators. One wheel at a time, unplug the double vacuum hoses from the actuators at the wheel (located behind the steering knuckle). Put your vacuum pump on the big hose fitting and apply vacuum. If it is working correctly you will be able to build up vacuum and it will hold. In this case the wheel should rotate and the front drive axle should not turn with the wheel (actuator disengaged by vacuum pressure). A vacuum loss of 1 lb over 1 minute is acceptable. If you cannot build vacuum or it leaks down very fast, the seals on the actuator are shot and the actuator needs to be replaced. In this case, when the wheel is rotated the drive axle will turn with the wheel (actuator not being disengaged by vacuum)

2. Next check your lines from the solenoid to the actuators at the wheel. Pull the double vacuum line off the solenoid. Pull the double vacuum line off of both actuators at the wheels. Plug the hoses at the wheels. You only need to plug the big hose at the wheel (the smaller line is the vent), and make sure you have a good plug that seals 100%. At the double hose that you took off the solenoid, trace the lines; you want the line that goes down to the wheels (should be the lower line), not the one that goes to the intake. Take your pump and connect it to the line end from the solenoid that goes to the wheels. Apply vacuum and see if the vacuum on the gauge holds. If it does not and leaks down, you have a leak in your lines between the solenoid and the actuators. Check the lines thoroughly from the solenoid to the wheels. It’s hard to get to some of the lines, but they all need to be checked. Look for cracks or breaks. Replace the lines with factory ones from Ford or make your own, with bulk vacuum hose and some fittings. If the vacuum you create with the pump holds, your lines are good but still look them over for obvious faults. You might also check to ensure no moisture or debris is in the lines. Drain and/or gently blow though the lines. Do NOT use high pressure air on any of this system unless you want to buy more new parts.

3. The vacuum reserve box is mounted behind the battery. You will have to remove the battery and battery tray to access and test it. Once removed and the vacuum line disconnected from it, connect your vacuum pump to the fitting on the box and apply vacuum, if it holds vacuum, it is OK. If it doesn’t build vacuum from the pump or leaks down, the box is leaking and needs to be replaced (Ford only part).

4. Now plug the line you removed from the vacuum box, this line runs to the intake with a "T" in it. The line from the "T" goes to the solenoid. Plug the end that goes to the solenoid also. Unplug the same line at the check valve that is close to the intake. Connect your pump to that end of the line and apply vacuum. If it pumps up vacuum and holds, that line is ok. If it won’t hold vacuum or leaks down, there is a leak in that line. Replace, repair, or make a new line.

5. There are two small check valves in the line coming off the intake. One close to the intake and one in the same line close to the solenoid. Pull those check valves off and check them. An easy way to check them is to blow (with your mouth, not compressed air-that will damage the valve) You should be able to blow air through one end and not the other. Or you can check the valves with the vacuum pump. One side of the valve will say "VAC" connect your pump to that end and apply vacuum. It should pump and hold without any leak down. If it does not then replace the valve. If it holds vacuum, the valve is good. If one or both of these fail, the high constant vacuum will not be held correctly in the system and while driving, the vacuum could drop too low and try to engage the actuators.

6. If all of this checks out OK, check the vacuum straight from the engine. Connect your pump to the line coming from the engine and start the engine. Watch what vacuum level shows on your gauge (you will not have to pump it). It should be anywhere from about 17 to 22. I’ve read that 20-22 is normal but mine likes to hover around 18-19 at idle. If this reading is too low you might have another vacuum leak somewhere else on the engine.

If you suspect that your system is malfunctioning and you are not able to test it right away or want to drive and not damage anything, disconnect the line coming off the intake at the check valve and plug both ends of the line. This will not allow any vacuum to reach the system and leave your hubs locked in all the time. This is fine and shouldn’t cause any damage as long as the hubs lock correctly. The half shafts and front driveshaft with the front differential will turn but the 4WD will not be engaged. You might notice a drop in MPG, but it is now safe to drive for a short term, until repairs can be completed.

Tools:

10mm socket or wrench, to change the solenoid

5/16” socket or wrench, to remove the IWE actuators from the wheel hubs

21mm deep-well socket, wrench to remove steering arm and control rod nuts (getting to the actuators)

Vacuum pump with gauge, for testing/troubleshooting vacuum system

 

pardon my nubness, but wheres the actuator? are you refering to the IWE? i hear these terms quite often.

 

Yes, in this case "Actuator" = "IWE."

 

I just took my truck for a quick spin to test it again. I have read and read and I just cant understand how it can work perfectly fine when engaged at a stand still, but when moving it fails to engage correctly. could it be that the vacum is less when driving as indicated in my readings? at which case there may be a blockage.

60dollars for a pressure tester or 100dollars for the dealer to correctly diagnose my problem. Im not sure what to do. I have an appointment tuesday.

 

I think my problem is here....

Out of these steps...
1. When the mode select switch (MSS) on the instrument panel is turned, the 4x4 module (PCM) activates the electromagnetic clutch and powers the transfer case shift motor.
2. When the shift motor reaches the desired position, as determined by the contact plate position inputs to the 4x4 module (PCM), power to the shift motor will be removed.
3. When the transfer case front and rear output shafts are synchronized, the spring loaded lockup collar mechanically engages the mainshaft hub to the drive sprocket.
4. Finally, the front axle integrated wheel ends (IWEs) are engaged and the electromagnetic clutch is deactivated.

Something in steps 1,2 or 3 is not happening and the IWEs are being engaged pre-maturely. This is forcing the grinding. This is my guess. I cant wait to see the dealer and see how much this is going to be...

Funny thing is here is the note that my "friend of a friend" mechanic said to give the dealer. Possible 4X4 control module. Will shift to 4h while at stop. will not shift into 4high while driving.

**edit**
been doing more reading lots are pointing towards the electro-magnetic clutch

 

Update

Yesterday I dropped my truck off at ford and they said they had seen a mud in the vacuum lines which solved the problem... then the problem came back again. They got a TSB notification and they were waiting for word back from ford.

Today, they got word that the TSB is not related to my vehicle. So service said they are going through the vacuum lines again. In the process they found that my PCM was bad and they ordered a new one. Thankfully covered under the 80mile, 8year warranty or whatever it was.

BTW. I kept insisting that the solenoid should be replaced and Have not heard any word on that.

So Im waiting for the new pcm to arrive, hopefully tomorrow, worst case monday morning.

Anyone ever have this problem?

 

So after everything was said and done. My solenoid was fine. I had a problem with my PCM. they replaced it under my 8 year 80k mile warranty. cost me 99 dollars for the clogged and cracked vaccum line.

 

So your 4WD issues are fixed now? All working correctly?