I have a 2001 F150 4x4 with automatic trans., 5.4L. It has the short 4wd shift lever on the floor.

Here is my problem: After I shift it from 4 wheel high to 2 wheel high, the 4x4 light stays on and I can feel some vibration at speeds over 45 mph. At this point though the truck is in 2 wheel drive. This indicates to me that something is still engaged. In the past when this happened I would park it for a while to cool down and then the light would not be on when I started it back up and no vibration when I drove it, indicating that something had finally disengaged on it's own.

Lately, it hasn't disengaged on it's own and I need to know what's going on here.

EDIT: here is a link that explains it all! https://www.ford-trucks.com/forums/9...97-2003-a.html

 

Sometimes you have stop and put the transmission in (N),(R) then back in (D) to get it to disengage completely

 

To get what to disengage? Like I posted, it's NOT stuck in 4wd, it's in 2wd with the 4x4 light on and something vibrating in the front.

 

<----That.
Q. What does the 4x4 light indicate to you?

 

I didn't really need a wiseass remark. You're reading comprehension leaves a lot to be desired. I'm not looking for a question. I'm looking for an answer.

Maybe someone else here with some mechanical knowledge can help me out.

If the transfer case is in 2w high, why would the 4x4 light be on? To simplify this, if I put the truck on a lift, only the rear wheels are spinning, and not the front. The front driveshaft is not turning. It's NOT in 4wd.

When I drive the truck there is a vibration coming from the front and the 4x4 light is on even though the transfer case is in 2w high. Does this mean the front hubs haven't disengaged? Will taking them apart and greasing them fix the problem? Is this a electronic problem?

 

so when you had it on the lift did you spin the front wheels to see if that would turn the driveshaft?

 

Your F-150 does not have "locking hubs", either manual or automatic.
The problem is likely the axle engagement actuator, that is located on the back side of the front axle. This is vacuum actuated. It probably needs to be removed and cleaned, then reistalled.

If you use the 'search' feature above, you may find that this issue has been covered many times and the answer is already here on this site, waiting for you to read and learn from.

If cleaning the actuator does not repair this issue, then it could be the two vacuum relays that are under the hood, on the firewall and under the electrical center.

Good Luck with your F-150.

 

Thanks, that's some good information. I did a search and didn't find anything that could help me. I'll check things out and report back with what I find.

 

Further, the system is GEM controlled.
If the 4x4 lamp is on with the lever in 2w, it is an off normal trouble indication.
Check the lever adjustments as well.
The GEM module lights the dash lamp indicators when it detects all conditions correct for a lamp action but as you see, you detect when there is an issue, as well.
Good luck.

 

I've been having a problem with the 4 wheeldrive staying engaged after I put it back in 2high, I have to stop and put it in reverse then drive, then it's ok. I figured this topic was covered before!
I'm gonna check out that axle engagment actuator, mentioned in the post.
Wasnt my original posting, but I learned something aswell..thanks!

Also, i'm looking to get a set of aftermarket rims to run just in the winter months and I need to know the lug pattern for my truck. 01 f150 4x4..
Thanks..

 

Here is a link to a thread by revytrucks that explains what I was trying to find in this thread. This should be a sticky.

https://www.ford-trucks.com/forums/9...97-2003-a.html

 

UPDATE:

My front differential won't disengage from 4wd.

Here is what I found today while checking things out:

I pulled the two vacuum lines (1 pink and 1 blue) off of the actuator unit on the front differential and found that only the blue line is sucking. This is the one that engages the differential into 4wd. No matter where I put the floor shifter, only the blue line is sucking.

I guess the solenoid for the blue line (4wd engage) is stuck open.

I'm wondering if replacing it will fix the problem or maybe a defective GEM is "telling" it to stay open?

 

Just so everyone is clear -- The 4X4 system operates on two different and almost seperate levels -- the transfer case which is manually engaged in this case by a floor shift stick and the front differential which is engaged by a vacuum actuator system with the GEM controlling solenoids which in turn contorl vacuum.

If your 4X4 light is on, it means that this front differential system has been activated, but does not mean the system has worked as planned and engaged. Also, removing the floor stick shifter out of 4X4 means your transfer case is disengaged, but if it still feels like it is in 4X4, then the front differential is still engaged -- locked up front wheels that arent driving cuz the drive shaft isnt turning.

Most 4X4 problems are with the front differential because of the different touchy systems involved while the transfer case is pretty simple

I am answering more about this problem in my other thread which has more detail.

https://www.ford-trucks.com/forums/92...97-2003-a.html

 

UPDATE:

The problem was a malfunctioning Transmission Range Sensor Switch part # 4L3Z 7E440 AB It is located on the left front of the transfer case. Depending on what position the 4x4 floor shifter is in, this switch tells the GEM which vacuum solenoid to activate for the vacuum actuator (on the front differential housing) to engage or disengage the front differential. It is also responsible for activating the "4x4" light and the "4x4 low range" light on the instrument panel.

Thanks revytrucks for the awesomely helpful info that explains how this system works!

 

Good to hear! Thanks for filling in more of the system too!