4x4 problems f 150 supercrew 5.4 2001, when i bought the truck the 4x4 didnt seem to work, i noticed the iwe or other words the vacuum solenoids were bad, replaced them and still have no 4 wheel. i then hit the actuator shaft few good times with a screw driver. it then was able to lock in 4x4 but not 4 low, i tried again later and the opposite happened only 4 low works, would this be a bad actuator or stuck shaft, a bad vacuum lines, or the transfer case motor, which i cant find any advice and information will be great! thanks'

This seems like it could be a IWE solenoid. This solenoid controls the vacuum which engages and disengages the hubs. It is located on the passenger side either on the fender behind the vacuum reservoir or on the firewall. The part# that you'll want is CX-2117. This is an updated kit that includes the solenoid and a cover to keep rain and moisture off and is cheaper than just buying the solenoid. One thing that you can try is to disconnect the vacuum lines from the IWE actuators(located on the half shafts behind the hubs). With the vacuum disconnected the hubs should be engaged and turn when in 4X4. I hope this solves your problem.

1st, pull the vacuum lines on the IWE ( Integrated Wheel Ends ) down on both front wheels. There are 2 hoses, 1 is the vacuum line to keep the IWE spring pulled out so the front axle is not engaged, the other is the vent line into the engine compartment ( not connected to any thing ).

The issue you have sounds a great deal like the TSB published for the IWE solenoid, where water can get into the vacuum system, and not completely disengage the IWE gear ( causing it to be part engaged, and ratcheting the teeth of the gears, wearing them down ).

The truck will feel like the parking bake is on, while the vacuum line is pulled ( you are pushing a dead axle ).

The vacuum line and IWE solenoid are easy to test with a vacuum gauge, to find out if it is the line, the IWE solenoid or the vacuum supply to the IWE solenoid.

The TSB in PDF format (right click save as : )
http://my.voyager.net/~sscully/file_tsb06_08_15.pdf

Here is a block diagram of the IWE vacuum system


Operationally vacuum holds the IWE ( Integrated Wheel Ends ) out, and once vacuum is removed the spring engages the IWE.

IF this is a case that the IWEs will not disengage, it could be the IWE solenoid or the vacuum lines to the IWEs. Could also be a problem with the vent lines from the IWE ( the other vacuum line that runs up into the engine compartment, and just hangs there ).

This is the block diagram of the vacuum lines for the IWE ( not actual routing ). You can use a vacuum pump / gauge to see if the lines will hold vacuum. Don't be surprised if the vacuum lines test OK, there is a TSB on the IWE solenoid where it could ingest water, and allow water in the lines, which will not keep the IWE gears disengaged.

Block diagram of the IWE system


TSB on the IWE solenoid ( right click save as )
http://my.voyager.net/~sscully/file_tsb06_08_15.pdf

I would check your fuses or connectors first. It is strange that you get no error codes or warning lights. Nothing! I am assuming that it is Electronic shift on the fly.
The integrated wheel end (IWE) system contains the following: Vacuum reservoir
IWE solenoid
IWEs (spring loaded vacuum hubs)
Vacuum hoses
Check valve
The IWE system uses vacuum hubs that engage the front wheel hubs to the front halfshafts or disengage the front wheel hubs from the front halfshafts. The IWE solenoid receives engine vacuum from the vacuum reservoir.
When the 4-wheel drive system is in 2WD mode, the 4x4 module (PCM) supplies a ground path to the IWE solenoid to apply vacuum to the integrated wheel ends (disengaging the front hubs from the front halfshafts). In 4WD mode, the 4x4 module (PCM) does not supply the ground path to the IWE solenoid, vacuum is not applied to the integrated wheel ends and an internal spring keeps the front hubs engaged to the front halfshafts.
There are issues with the 4x4 system I.w.e ends ingesting moisture/water into vacuum actuation system causing no 4x4 or ratcheting outboard I.w.e ends. (Even if you don't go 4x4'n ) pull off vacuum hoses @ I.w.e ends and check for moisture/water/rust also the I.w.e is not part of the wheel bearing itself It is the part on the axle side (inboard) of the spindle. (EVEN DEALERS CAT LISTED WRONG )Many shops just replace the wheel bearing side this may fix the symptom but not the true cause of damaged I.w.e. ! Check with a reputable dealer they should have info on this condition and repair procedure.
Good luck and start with checking the IWE system in the front end.

Today and over the weekend .I too had the same problem. Took it to the dealer and they tested everything and could not find the problem. Did vac test on the lines, Test drove it with code tester to see if there was any problems . Checked the hubs... They replaced the IWE solenold. Just hope that is the fix and it didn;t damage anything else... Thanks for the above info!

There are issues with the 4x4 system I.w.e ends ingesting moisture/water into vacuum actuation system causing no 4x4 or ratcheting outboard I.w.e ends. (Even if you don't go 4x4'n ) pull off vacuum hoses @ I.w.e ends and check for moisture/water/rust also the I.w.e is not part of the wheel bearing itself It is the part on the axle side (inboard) of the spindle. (EVEN DEALERS CAT LISTED WRONG)Many shops just replace the wheel bearing side this may fix the symptom but not the true cause of damaged I.w.e. ! Check with a reputable dealer they should have info on this condition and repair procedure.


The integrated wheel end (IWE) system contains the following:

Vacuum reservoir
IWE solenoid
IWEs (spring loaded vacuum hubs)
Vacuum hoses
Check valve
The IWE system uses vacuum hubs that engage the front wheel hubs to the front half shafts or disengage the front wheel hubs from the front half shafts.

The IWE solenoid receives engine vacuum from the vacuum reservoir.

When the 4-wheel drive system is in 2WD mode, the 4x4 module (PCM)supplies a ground path to the IWE solenoid to apply vacuum to the integrated wheel ends (disengaging the front hubs from the front half-shafts). In 4WD mode, the 4x4 module (PCM) does not supply the ground path to the IWE solenoid, vacuum is not applied to the integrated wheel ends and an internal spring keeps the front hubs engaged to the front half-shafts.

Operationally vacuum holds the IWE ( Integrated Wheel Ends ) out, and once vac is removed the spring engages the IWE.

Lift and support the front of the truck so the front wheels are off the ground ( take safety precautions, chock wheels, jack stands, etc )
Key on, engage 4x4 and try to turn the front drive shaft.
If it turns it is a problem with the transfer case.
If it doesn't it is a front axle engagement problem.

- If the front drive shaft does not turn :
Shut of the truck ( still jacked up, and supported ) remove the vac lines from the IWE. The spring should push the gears in, without the vac line on.
Check the vent line ( tube that is routed into the engine compartment with nothing attached to it ), for blockages.
If the vent line is clear, and with the vac lines off the IWE should be engaged ( both front wheels locked ).
If they lock, the problem is with the IWE solenoid not shutting off vacuum to the IWEs. There is a TSB on the 2004-2006 IWE solenoids, a newer revision has been made, and used from 2007 and newer MYs.

Here is a block diagram of the IWE system

Could be cracked vacuum lines to the IWE ( Integrated Wheel Ends ) or a faulty IWE solenoid.

The IWEs are held out with vacuum, and when 4WD is selected, the vacuum is shut off, the vent tubes relieves the vac as the spring engages the IWE gears.

I would lean towards faulty vacuum lines for the IWE system ( to the IWEs themselves, from the vacuum box, or the vacuum box itself ).
You can check them by disconnecting the vacuum line from the IWE, and checking with a vac gauge or apply vacuum with a pump.
Start with selecting 4WD ( engine running ) , so you can test to the IWE solenoid from the IWEs, and then work back towards the vacuum reservoir ( located behind the battery box ).

The IWE solenoid could be the problem, there is a TSB where the revision used on the 2004-2006 could ingest water, and introduce it to the IWEs, causing a problem.

Here is the block diagram of the IWE vacuum system:


This is a PDF version of the TSB on the IWE solenoid, so you have it handy :
http://my.voyager.net/~sscully/file_tsb06_08_15.pdf

If you do not have time to get to the testing right away, I suggest pulling the Vacuum lines to the IWEs, and capping them off. This will leave the IWE engaged ( front axle locked, but not beign driven ), do you don't have the engage, disengage problem, which could damage the teeth on the IWE gear. Just watch how fast you try to drive, the truck will not like pushing a dead axle at 95 mph.

Sorry, brain fade this AM, posed clarification, not a solution ( no picture )

It could be the IWE ( integrated Wheel Ends ) or the IWE solenoid not allowing the IWEs to engage. Might want to check ( at a minimum ) the IWE solenoid to the IWE, and the vent from the IWE ( to make sure it is clear of obstructions ).
This is the block diagram of the IWE vac system

Vac is applied at the IWE to keep them disengaged. When VAC is removed, the spring in the IWE should push the gears together and lock in the front wheels to the axle. There was a 2004-2006 TSB on a faulty IWE solenoid that could intake water, and allows water to flow to the IWEs, causing problems. Keep that one in the back of your mind as you look for problems.
Link to a PDF copy of the TSB
http://my.voyager.net/~sscully/file_tsb06_08_15.pdf

Could be a cracked vacuum line to the IWE at the front wheels.

You can test with a vac gauge at the wheel to see if is there.

There is a vacuum reservoir box behind the battery box. This leads to a T on the firewall area. 1 end to the back of the intake w/ a check valve inline, the other end to a check valve to the IWE solenoid behind the battery on the firewall ( in the PCM area, those 3 large connectors ).

From the IWE solenoid the line runs to a t, and to each IWE.

I would start with checking for VAC at the IWEs, some times cracked lines do happen at the IWE. NExt would be the IWE solenoid if the fuse is good.