Everything You Wanted To Know About The IWE System....And Then Some!
#31
01-29-2012, 08:09 PM
#32
01-29-2012, 10:00 PM
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The rerason this is happening is that the whole IWE system depends on vacuum. At rest (no vacuum), your IWE's are actually locked. Start the truck up - or put it in 4WD - and the system applies vacuum to the IEW's and disengages them.
Now to your point. You either have (or had) a vacuum leak someplace or an IWE go bad in the past. What's happening now is that it's partially disengaged and thus the grinding noise. It may be a bad Solenoid, Vacuum Line or Check Valve that caused it and you need to track it down. But, since your IWE has been partially disengaged for so long, it's probably bad too.
Hope that helps.
Now to your point. You either have (or had) a vacuum leak someplace or an IWE go bad in the past. What's happening now is that it's partially disengaged and thus the grinding noise. It may be a bad Solenoid, Vacuum Line or Check Valve that caused it and you need to track it down. But, since your IWE has been partially disengaged for so long, it's probably bad too.
Hope that helps.
#33
01-30-2012, 06:31 AM
That helps my knowledge and diagnosis a ton but help my wallet absolutely none!!! Seriously though, thank you for your insight on the issue. I just got a wild hair and decided to get on here and take a look and bam, there it was, similar symptoms and all. Once again, great site and great members here. Thanks for the help.
#34
02-01-2012, 11:04 PM
I'll start by saying I'm not very mechanically inclined in the first place but when I started researching the issues I was having (it would sporadically try to engage while driving for no reason) and ran across this thread I decided I could give this a try. I am without question having vacuum leak issues. The IWE's are both engaged while the truck is running. They appear to be working fine when I hook the vacuum pump up. They both release at exactly 5. They also will hold 20 for a couple of minutes without a problem. I am having trouble when it comes to checking the lines down to the wheels. Can someone tell me (or pics would be great) exactly where I need to hook up the pump to vacuum the lines down to the wheels. I unhooked the lines from the solenoid and pulled them out to where I could get to them. I went below the air check to a T. The drivers side of the T goes back to the other air check and appears to the manifold. I hooked the passenger side of the T and hooked the pump up with the lines off the wheels and plugged once and connected to the wheels once. They both hold pressure just fine. The problem that I have is when it is connected to the wheels this did not disengage the IWE. I either have the wrong line and am vacuuming the Vacuum box or the line is clogged. I think I may just have the wrong line though. I did not take the battery and box out as I did not have time at this point. If I dont get it fixed by saturday that is the next step.
Thanks for the helpful information so far as I am sure it has already saved me a fortune from not having to take it to the dealer for something that so far seems fairly simple.
Thanks for the helpful information so far as I am sure it has already saved me a fortune from not having to take it to the dealer for something that so far seems fairly simple.
#35
02-17-2012, 01:37 PM
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XJ, great write up and guidance along the way for everyone with IWE issues. Hopefully you can help me with mine. For a few months now I've been getting the 4wd to engage only part of the time. Sometimes it never skips a beat and sometimes it doesn't beat at all. I don't hear any grinding noise or any of that. I did replace the IWE solenoid and it worked immediately after that (although it could have just been one of the times it decided to work.) Recently it hasn't worked at all. My guess is that the transfer case motor is bad and should be replaced. What are your thoughts? I haven't tested the vacuum lines, but it seems like the vacuum lines are only an issue if you're hearing grinding noises. Is that true? Any advice you (or anyone else can give me) would be greatly appreciated. Thanks.
#36
02-17-2012, 02:28 PM
XJ, great write up and guidance along the way for everyone with IWE issues. Hopefully you can help me with mine. For a few months now I've been getting the 4wd to engage only part of the time. Sometimes it never skips a beat and sometimes it doesn't beat at all. I don't hear any grinding noise or any of that. I did replace the IWE solenoid and it worked immediately after that (although it could have just been one of the times it decided to work.) Recently it hasn't worked at all. My guess is that the transfer case motor is bad and should be replaced. What are your thoughts? I haven't tested the vacuum lines, but it seems like the vacuum lines are only an issue if you're hearing grinding noises. Is that true? Any advice you (or anyone else can give me) would be greatly appreciated. Thanks.
#37
02-17-2012, 02:54 PM
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The first question I'm going to ask is about when it doesn't go into 4x4. Does the indicator on your dash say it's in? If so, you have an IWE / vacuum problem because the transfer case is shifting. If the indicator doesn't show it's in, then you have an ESOF motor problem. If it looks like an ESOF problem, you might want to put the truck up on a lift and have somebody move the selector switch back and forth while listening for the motor moving the shift fork. If it doesn't move - and has power to it - the motor is quite easy to replace.
#38
02-17-2012, 06:49 PM
The short answer is "test light." I don't have a wiring diagram handy, but if you ground the test light, you should have power to at least one of the wires in the modular plug. If the motor doesn't start when your friend moves the selector switch, try lightly tapping the side of the ESOF motor. This will sometimes wake one up. If it does though, the motor is probably on the way out the door.
#40
01-29-2019, 02:32 PM
#41
02-16-2021, 10:07 PM
To test the vaccum system, get a good vacuum pump with a guage on it, about $60 (or cheaper) at alot of parts stores.
-If when you try to shift into 4WD and it will not engage, most likely your solenoid is not working and releasing the vacuum to the actuators and engaging the hubs. Replace the solenoid. This might happen because of the early design of the IWE solenoid with lets water run off the cowl right down on top of the solenoid possible shorting it out. The new style solenoids have a rain cover on them to prevent this. This is all being said as long as you know your shift motor on the side of the tranfer case is working properly.
-If your in 4WD and it will not shift out, the solenoid is not opening back up to let vacuum release the actuators. Replace the solenoid. Again if the shift motor is working.
-If you hear a grinding or whining of gears at certain speeds or loads you probably have leak in your vacuum system somewhere and your vaccum is dropping to or below the 5 lbs of vacuum needed to keep the actuators unlocked. Check the following:
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 pump up the pump. If it is woking correctly you will be able to build up vacuum and it will hold. A vacuum loss of 1 lb over 1 minute is acceptable. If you can not build vacuum or is leaks down very fast, the seals on the actuator are shot and the actuator needs to be replaced.
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 a the wheel, 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, 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. Pump the pump up and see if the vacuum on the guage holds. If it does not and leaks down, you have a leak in your lines between the solenoid and the actuators. Check the lines very thoroghly from the solenoid to the wheels, its hard to get to some of the lines, but they all need checked, look for cracks or breaks. Replace the lines with factory ones from ford or make your own, like i did 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.
Then you will want to check the vacuum reserve box that is mounted behind the battery on the battery tray. You will have to remove the battery and battery tray to access it. Once removed and the vacuum line disconnected from it, connect your vacuum pump to the fitting on the box and pump up the pump, if it pumps up with vacuum and holds it is ok. I fit doesnt build vacuum from the pump or leaks down, the box is leaking and needs to be replaced (ford only part).
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 pump up the pump. If it pumps up vacuum and holds, that line is ok, if it wont pump up or leaks down then there is a leak in that line, replace, fix, or make a new line.
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, this will blow them out, i know) You should be able to blow through one end and not the other at all. Or you can check it with the pump. One side of the valve will say "VAC" connect your pump to that end and pump it up. It should pump and hold without any leak down. If it does not then replace it. If it holds its 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.
If all of this checks out ok check the vacuum straight from the engine. From the line coming off the engine connect your pump to the line and turn on the truck. Watch what poundage of vacuum shows up on your guage (you will not have to pump it up) should be anywhere from about 17 to 22. Ive 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 when you try to shift into 4WD and it will not engage, most likely your solenoid is not working and releasing the vacuum to the actuators and engaging the hubs. Replace the solenoid. This might happen because of the early design of the IWE solenoid with lets water run off the cowl right down on top of the solenoid possible shorting it out. The new style solenoids have a rain cover on them to prevent this. This is all being said as long as you know your shift motor on the side of the tranfer case is working properly.
-If your in 4WD and it will not shift out, the solenoid is not opening back up to let vacuum release the actuators. Replace the solenoid. Again if the shift motor is working.
-If you hear a grinding or whining of gears at certain speeds or loads you probably have leak in your vacuum system somewhere and your vaccum is dropping to or below the 5 lbs of vacuum needed to keep the actuators unlocked. Check the following:
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 pump up the pump. If it is woking correctly you will be able to build up vacuum and it will hold. A vacuum loss of 1 lb over 1 minute is acceptable. If you can not build vacuum or is leaks down very fast, the seals on the actuator are shot and the actuator needs to be replaced.
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 a the wheel, 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, 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. Pump the pump up and see if the vacuum on the guage holds. If it does not and leaks down, you have a leak in your lines between the solenoid and the actuators. Check the lines very thoroghly from the solenoid to the wheels, its hard to get to some of the lines, but they all need checked, look for cracks or breaks. Replace the lines with factory ones from ford or make your own, like i did 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.
Then you will want to check the vacuum reserve box that is mounted behind the battery on the battery tray. You will have to remove the battery and battery tray to access it. Once removed and the vacuum line disconnected from it, connect your vacuum pump to the fitting on the box and pump up the pump, if it pumps up with vacuum and holds it is ok. I fit doesnt build vacuum from the pump or leaks down, the box is leaking and needs to be replaced (ford only part).
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 pump up the pump. If it pumps up vacuum and holds, that line is ok, if it wont pump up or leaks down then there is a leak in that line, replace, fix, or make a new line.
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, this will blow them out, i know) You should be able to blow through one end and not the other at all. Or you can check it with the pump. One side of the valve will say "VAC" connect your pump to that end and pump it up. It should pump and hold without any leak down. If it does not then replace it. If it holds its 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.
If all of this checks out ok check the vacuum straight from the engine. From the line coming off the engine connect your pump to the line and turn on the truck. Watch what poundage of vacuum shows up on your guage (you will not have to pump it up) should be anywhere from about 17 to 22. Ive 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.