XJC89, Thanks again. Now that deer season is about over and I have a vacuum gauge, I'm about to attack this problem. Should be easy now, thanks mostly to YOU!

 

Glad i could help!

 

I appologize if this has been answered here, but I have a limited amount of time to use the internet at work, so here goes:

My 2007 f150 seems to be dragging the front wheels when turning in 2x4. It feel like the hubs are locked, but not in 4x4. I just left the local repair shop and the mechanic states there is nothing wrong. While on the lift he was spinning the wheels and the cv joints(axels?) where turning the front shaft and who knows what else inside the gear box.

I tried to explain that the hubs were locked, but this guys believes they are always gonna turn the axles or joints and shaft. My knowlege of the vacum system is limited to a warranty issue i had at 30K, ford fixed it.

So, do the wheels have hubs that lock into the axels? Do the wheels always spin the front drive train? Sorry if this dont make any sense, I tried to read the first few pages and I'm still lost.

Thanks in advance-John

 

FLAT....you are right and your mechanic is wrong. The axles should NOT turn when the wheels are spun, with the TRUCK RUNNING and NOT in 4x4. (You didnt state if the truck was running or not) If they are spinning, like you stated, and your truck was running, you need to diagnose where your problem is. It could be a bad IWE solenoid, bad check valve, leaking IWE, or leaking vacuum line. You need to get a vacuum guage to properly narrow down your problem. If you do not want to go that route, I would take it a dealership or another shop that understands the vacuum systems on these trucks, because if they dont, you might end up paying for alot more than what is actually wrong if the wrong place just starts throwing parts at it. If your mechanic really beleives that it is fine and that the spinning axles are normal, than i would definately not let him repair it, because he just proved to you that he doesnt understand these systems.

If you go the home diag. and repair, get a vacuum guage and take your time and read the beginning of the thread and the diagnostics. You will find your problem, it might sound tedious but the problem willl be obvious when you find it with the guage.

Let us know if you need any help.

 

Thank you for your response. I overlooked the engine running part, we lifted it NOT running, but I can tell by the drag when turning and my mileage/accelleration that its gotta be the hubs. I will return tommorow to check it while running. Thanks again-John

 

let my start off by saying that the info was great. Thank goodness for people like you wanting to help. I read this forum alot but not much of a poster. I need help. 05 screw 4X4. 64,000 miles. It snowed today and now I have no 4X4. I have never heard any grinding noise around the front end at all. No noises what so ever to alert me of any trouble. I can hear the transfer case kicking in when switched to hi and low. The dash indicators light up in both gears but no power transfered to the front tires. I pulled the vacuum hoses from the IEW on the firewall and had vacuum. I then pulled the vacuum hoses at each tire and plugged them. I am thinking that this should have caused the hubs to remained locked so when I engaged the transfer case the truck should have been in 4 wheel drive. It however remained in 2 wheel drive. I think that I have included all vital info so if anybody has any ideas or advice, please share. I have a 4X4 stuck in my driveway and my wife's Toyota in garage with a recall saying the gas pedal could stick and kill the family. What a weekend!!!! Thanks everyone

 

i know that the transfer case switch motor can malfunction and not lock in the transfer case, but usually when that happens the dash lights dont come on. And you are right, if you unplugged the vacuum lines at the hubs and plugged them then the hubs will lock hence when your switch your 4WD on you should be in 4WD. What might be happening is that your transfer case switch motor is partially working (you hearing the click) to the point where it trips the dash light but isnt engageing the transfer case fully. Just a thought. I havent really seen this before but it is possible. Or (not very likely) your IWE hubs are stuck in the unengaged position (no matter if they have vacuum or not) and your transfer case is woorking correctly. Not sure how likely that is but im sure its possible. You need to get a vacuum guage and check the IWEs. Jack the front of your truck up and hook the vacuum tester to the large vacuum port on the IWE, spin the wheel without vacuum applied, the wheel and axle for that side should spin. Now apply vacuum, at least 10 (whatever the measurement is) and see if it holds, and then spin the tire. The vacuum you applied is like the vacuum your truck applies, it should release the IWE and when you spin the tire again just the wheel should spin, not the axle. If those tests conclude like that after testing both sides then your problem isnt a IWE. You could then check all the vacuum likes and check valves like in the my first post, and if they all check out fine, i would try a new transfer case switch.

Or what you could do is go get a new transfer case switch motor, put it on, test it, if it fixes your problem your good, if not, pull the new switch motor off clean it up and return it. Then focus on the vacuum side of the system.

 

Thanks for all the info XJ, your crash course write up was very useful. I don't understand all the trouble that I had this weekend, but come Sunday the weather warmed up and the 4 wheel drive began working flawlessly. I am going to follow your advice and check all vacuum and I also ordered another IWE solenoid with the weather guard. Hopefully it will all be good. Thanks again for your reply and sharing your knowledge.

 

below freezing and the system didn't work, above and it does? Could there be some water in the system/lines that prevents the vacuum from working properly? (when frozen)

 

Hey 60DRB, I am far from being a expert on this matter but based on my problems, I do think that was my problem. I had the old solenoid without the water guard on when my problems started. I think that when I started removing all the vacuum lines and testing them that I actually got rid of some water and grime that was in them. I replaced my old solenoid with the new one with the water guard and I have had no more problems when it rained, snowed and in freezing temps. Hopefully that is your only problem, it is worth a try and a very inexpensive fix. Hope this helps.

 

Yes, water in the lines freezing or water in the IWE itself freezing will keep the system from working properly

 

Thanks for a most informative thread, now here is the curved ball, I have an 07 Harley with AWD, I understand that the Control Module makes the decision on when to apply power to the front wheels when in AWD. Question; does it do it at the transfer box or through the IWE's?
I know I could work this out by jacking the truck in the air & getting dirty but as I don't have a problem at the moment, or a nice warm workshop, I just wondered if anyone knows a bit more than I do!

 

I am having some isseus with my 4x4. I have read your post and it is amazing and really familiarized me with the IWE Hubs and Vaccuum. Here is my issue though.
I have checked the vaccuum lines as far as damage or leaks and I have not found any. I also disconnected the vaccuum from the engine to make the hubs stay engaged. Still when I drive in 2WD I hear a grinding noise coming from my hubs especiallt the passenger side. When I put it in 4H the noise goes away but then it clunks every once in a while and I try to take it insome sand and mud and my 4WD is not working. I am pretty sure it is a mechanical problem in my hubs. Do I need to replace my hubs? If unsure is there a better way to test? Also, basically I need to know where to start. If anyone can help me I would greatly appreciate it.
Tim

 

I tested the vaccuum lines and also disconnected the vaccuum line and pluged it from the engine. Still when I drive I hear a grinding noise (gears spinning) when I drive in 2WD. If i put it in 4H the noise goes away but it will clunk like it is slipping out of 4WD. I have taken it to a little mud and realize that my 4WD is not really working and have narrowed down to the hubs (I THINK). Is there a better way to test it to be sure? If it does sound like I need to replace the hubs where do I start, or what else sould it be?
I bought the truck like this and am pretty sure it was from the guy not shifting into 4WD correctly and messing something up. It is a 2005 FX4. Does anyone have any advice? Thank you,
Tim

 

I tested the vaccuum lines and also disconnected the vaccuum line and pluged it from the engine. Still when I drive I hear a grinding noise (gears spinning) when I drive in 2WD. If i put it in 4H the noise goes away but it will clunk like it is slipping out of 4WD. I have taken it to a little mud and realize that my 4WD is not really working and have narrowed down to the hubs (I THINK). Is there a better way to test it to be sure? If it does sound like I need to replace the hubs where do I start, or what else sould it be?
I bought the truck like this and am pretty sure it was from the guy not shifting into 4WD correctly and messing something up. It is a 2005 FX4. Does anyone have any advice? Thank you,
Tim