I have a 2009 F150 FX4, when I try using 4WD everything seems fine if 4WD High, if 4WD Low it does not seem to properly engage. At times it seems when switching back to 2WD it doesn't always reengage immediately. There are times I have had to drive around to switch back to 2WD. I have had this problem since I purchased so cannot be sure when it started

Thanks for helop

 

Probably hasnt been used enough, which is one reason I dont want 4wd on a daily driver.
You can do one of two things:
1. Dont use 4lo anymore.
2. Try to actuate it back and forth from 4hi to 4lo a bunch of times. Do that by switching to 4lo, drive it around off road for a few minutes then switch it back to 4hi, then 2wd.
If you choose #2 , do it at least a few times a week and if it seems to shift to 4lo and back more seemlessly, then try to remember to engage 4hi and then 4lo once a month.
Keep in mind that you will want to shift to 4lo only in neutral. If the truck is rolling slightly forward during the 4lo shift that will help it.

Its also a possibility that the shift motor is getting tired.

 

are/were you stopped and in neutral when attempting to switch into 4L?

 

Yes, I have learned I need to be in neutral and wait to see dash say engaged as well as when switching back to 2wd. I didn't realize I bid on truck at auction so I have had this problem since I bought truck

 

See if backing up and going forward will allow an easirer disengagement. Certainly used to work in the days of manual hubs.

 

Thanks, I can try that, like you I really don't use 4WD the main thing is I have used it when had to pull something stuck in mud, if I can get to work proper I will try to drive it in 4WD once or twice a month. I have been told it could be something with module too. As I stated, I didn't realize I bid on with auction so know little about the vehicle

 

what is the level and condition of transfer case fluid ?

 

It was a pain to get to the dipstick to check transmission fluid but it is full and looks good, How often does fluid need to be changed?

 

transfer case is not the transmission. Different parts, different fluids.

suggest finding fordtechmakeuloco on YouTube and watching as many videos related to your truck as you can.

 

If you don't use it, you lose it. Virtually all 4X4 issues can be traced back to operator error. Most owner's manuals recommend 10 miles/ month in 4X4 to keep everything lubricated and to prevent corrosion in electrical connections. IME 10 miles each and every month may be overkill, but I try for at least 2-3 miles most months. I won't skip 2 months and at certain times of the year I may get in 200-300 miles some months.

If the previous owner didn't use it regularly taking it out on a dirt or gravel road and giving it a long drive switching back and forth often will usually help. Or you may need to have the hubs taken apart, cleaned and reassembled. Possibly even some parts replaced.

Getting into, and out of lo range is often problematic with all 4X4's. The owner's manual doesn't say to be at a complete stop, it says to be stopped or moving under 3 mph. Often it will engage at a complete stop, but sometimes it won't. I like to stop on a slight incline and let the truck roll slowly in either direction as I'm engaging or disengaging low range. While it is technically possible to shift directly from 2wd to 4 low I find less issues doing it in 2 steps. Shift from 2wd to 4hi while driving. Once the shift is complete stop or slow under 3 mph, shift to neutral, then to 4 low. I find it easier to get out of 4low by going to 4hi, then once underway shift back to 2wd.

If you've been in low range getting out can be especially problematic. The gears often bind if you've been working the truck hard. Especially on a hard surface where it is borderline on even needing 4X4. Driving the truck in reverse 10-15', then pulling forward will help relieve the binding. You may have to repeat this little dance several times.

If you have a locking rear diff be sure to engage it occasionally too.

Avoid operating in 4X4 on a paved road, even wet pavement. Even off road on surfaces with good traction such as hard packed dirt. Doing so puts the entire drivetrain in a bind and will eventually lead to premature parts failure. Very limited use, if you drive in a straight line theoretically won't hurt anything. But I advise against doing it by design. Virtually everyone has a brain fart occasionally and does something like this for a short distance. I just don't recommend doing it by design . Get the truck out on a road with loose dirt or gravel when operating in 4X4 so there can be some wheel slippage without binding everything up.