4WD Won't Engage
 

Tried to turn the 4WD on today just for the hell of it and it won't turn on. I don't use it much, but I do turn it on every now and then to keep it lubed. What are some of the common problems that cause this? I figure it's probably something electrical or a vacuum line or something? I don't really have a clue, but I'm hoping it's cheap. Even though I hardly ever use it, I'm still bummed that it doesn't work. Everything else runs perfectly fine.

Does the 4wd light come on? If it's not used in a while the 4wd shift motor freezes up. Solution is to put it in 4wd and hit the shift motor (on the back of the transfercase) with a hammer a few times to unfreeze. Then make sure you put it into 4wd from time to time.

Agreed, this "technique" works like a champ. Had to do it just last week prior to the big storm in the Northeast. My only question, is this a permanent fix, or do we have some corrosion going on that will force me to fix the shift motor? Any idea if this is covered under Ford's powertrain warranty?

Try reading this thread - which apparently many people didn't:

https://www.f150online.com/forums/20...ore-snows.html

No the light doesn't come on.

i believe i remember reading that another member had the same or similar problem and replaced the solenoid. the old style without the rainhood was prone to cracking. if water gets in and shorts or corrodes it and the solenoid cant move that might be part of the logic that turns on the light. if you have the old style solenoid it might be worth replacing out of preventative maintenance. could save you an IWE bill down the road

Any body have a pic of what exactly I should be tapping?

Got it fixed! A little tapping did the trick. Boy that's a load off of my back. I knew it was probably something simple, but figured it would cost me. Who knew it would be this simple. Thanks for the suggestions!! This is why I love this forum.

i have been contemplating replacing that 4 wd motor as well as the fuel pump module.

Glad it worked out.


Has anyone taken the shift motor apart? Mine still sticks from time to time, it would be interesting to see if there is a place in the motor to grease to prevent it from sticking.

I don't know if they've changed the motor much from the 92 and 96 Explorer days, but if not, it's just a permanent magnet electric motor, no particular need to grease, and no need to replace, unless it quits altogether.

Just exercise it once a month, run it to 4-Hi and 4-Lo, back to 2wd, and forget about it until the next month, or until you need it. You don't even need to actually do any driving, just run it through it's paces.

I dont necessarily agree that engaging 4 HI every month will always ensure the shift motor will work when you need it. For example, recently I used 4 HI virtually non-stop for two weeks, then didnt use it for 1.5 weeks, then when I went to engage again, no joy...had to persuade it with a hammer. Its only froze on me twice in the 5 years I've owned the truck so I'm not too concerned with it.

I am having the same issue with 4WD not engaging. I have a 06 F-150 with 26k miles. Can someone post a picture of where the vacuum solenoid is on the firewall? If it is an easy fix....I will try it myself.

Currently I have an appointment at the dealer to look at this on Tuesday. I would much rather try to fix it myself....it I can and if it is not that difficult.

Before you check or worry about the solenoid, lets see if its a transfercase problem. When you shift to 4wd, are you getting the 4wd light?

No...the 4H and 4L lights do illuminate when I first start the truck. Other than that...they do not illuminate when I switch to 4H or 4L.