I have a 07 f-150 5.4 XLT. I just had gotten stuck in 2H in some deep snow. I stopped then i turned the swith to 4H. the 4x4 light came on and i thought i heard it engage, so i started to accelerate to get the truck out. but the rear wheels started spinning again and i heard a "clicking noise" from the front end the 4x4 wasen't engaged, so i let of the gas and then it "Clunked" and the 4x4 started working. everytime i get stuck in 2h and then swith over to 4h the rear wheels will spin then the front end will make that "clicking noise" until i let off the gas, then it will "Clunk" into 4wd. it only does this when i get stuck in 2h and swith over to 4h to get it out. It does fine if i am not stuck in or spinning in 2h and switch to 4h.
it's weird to me i thought it's supposed engage the 4wd as soon as i turn the switch weather i am stuck or not. i can't prove it to the dealer because the truck is not stuck there. this has happened alot when i start to spin in 2h swith to 4h (i even wait a few seconds) then start to accel and the rear wheels spin. front end clicking noise and once i let off the gas, "Clunk" 4x4 engaged. i don't want cause any damage to the 4wd, so i am asking for suggestions. truck has 38,000 miles Thanks

 

My guess is that the clicking noise is the solenoid trying to engage and the clunk is the transfer case finally engaging. I believe there is some latency to the 4wh gear engaging when you're at a stand still compared to it engaging when the truck is rolling. I believe what you're experiencing is normal.

 

Things like splines or dogs have to line up first, it's not just a clutch engaging. When you switch from 2H to 4H, go real easy on throttle until you hear the "clunk" of engagement.

If stationaty, I make sure to stop all wheels, place in park, then switch, then pull into gear, and gently accelerate to allow engagement when all are lined up.

I only shift from 2H to 4H or back "on the fly" if I am actually moving and while still on slick stuff, before any dry pavement.

If I've used 4h or 4L in the yard, I'll pull up to where I know I'm not going to get stuck, stop, place in park, slip into 2H, and then back up.

 

Would putting the truck in N and brake trick help to get it into 4h easier. I am new at the 4wd truck. Just a thought.

 

^ Yes. It sounds like his rear wheels are spinning when he's stuck and throws it into 4H. The truck either needs to be motionless, or with all 4 wheels moving to use it "on the fly". When the rears are spinning and he puts it in 4H, it starts the driveshaft spinning up front, but the wheels aren't so it grinds. Then it clucks (more lig a big load bang) when it finally lines up and engages. Good way to f' it up if it continues. Neutral will help, but isn't necessary IF the rear wheels aren't spinning. I did that in some mud once, and was like "yikes".