toole05

Let it roll back bout one foot it will engage mine does it as well

Haerr

Parking brake does not need to be engaged but you do have to be stopped with your foot on the brake in neutral any time you go into or out of 4Low 4High is shift on the fly up to 55MPH. If you don't stop completely with the truck in neutral and your foot on the brake the 4Low will not engage or disengage

Bigbucks243

Put it in neutral. Lol.

Tradesman

Good stuff, I'm going to try it out!

KC5-0

I ran into this a couple of winters ago. The 4wd system is controlled with vacuum hoses. Mounted to the fire wall on the passenger side is a small black plastic cylinder with two or three small hoses going in to it. What happens is that on the older trucks I think 04-06 water runs on that and it manages to get water into it. Ford discovered the problem and re engineered the piece with a hood for the 07-08 models that protects the piece from rain water. Sorry I don't remember what the part is called there is a thread on here somewhere. If you can find it that will be a big help. I replaced the part with the new style and have not had any problems since. Hope this helps.

'08f150stx

http://www.ford-trucks.com/forums/83...then-some.html

If you think you have issues, here is a worth while link. Worth while even if you don't.
I don't know if this might be an iwe solenoid issue, but I had a hard time putting my truck into 4lo the first time, but after I got it there, getting it out of 4lo was a challenge also.
I just didn't know the procedure, but alas it was in my owners manual. I just had not read it.
Good luck!

King_Ranch_Pilot

Thanks guys, great info here. I'm gonna take it into a buddy of mine to have him look at it because even if I have it in neutral with the brake on, it still does not engage. Even tried letting it roll down hill. I will keep everyone updated as to what the problem is.

Tradesman

I tried it this afternoon briefly and it kicked in. The whole truck actually lurches forward a bit when it kicks in so you definitely know it's working, aside from the 4LO indicator on the dash.