i'm new to the whole 4x4 system here. When you engage 4x4 is it normal to be able to "know" your in 4x4 like you can feel the "vibration" under load or power being delivered to the front wheels. I have a 2006 fx4 and the 4x4 works great but i just wanted to make sure its normal to deff feel the truck being in 4x4.

 

I feel the difference in the pedals but that's about it. I guess if I'm at higher 4x4 speeds I can tell but I rarely go faster than 20 or so in 4wd

 

yeah, i guess thats the same with me. I feel it in the pedals and the steering wheel.

 

I know when I'm in 4x4. but thats because I've spent years driving the truck and notice slight differences. With that being said, I'm not sure it should "vibrate." One distinct difference would be the steering though

 

Does anyone know what the recommend speeds are for 4 high and 4 low?

 

I shouldn't say vibrate, you know how hard it is to describe stuff by writing haha. I guess you put it best, after driving it long enough you can tell. For me its the steering and power feeling going to the front end.

 

You can do highway speeds in high range if necessary.

I did read a post once of a guy (somehow) didnt realize he had it 4hi for a 4 hour trip all highway and posted this because he was a but panicked if he hurt anything. Concses was maybe do a fluid change in the drivetrain if he was really worried but its probably fine. This was long time ago I read this. I believe it was on previous gen, the pre 04.

I use mine at freeway speeds if I need to go around somehow and they haven't cleaned up the passing lane. Not find of the wiggle itll do under acceleration otherwise...

 

you will feel a differance in 4 high esp if you know the truck well. its fine to use 4 high at high speeds in snow. the reason being is that you want the front tire to be able to slip in turns a little. You will know what I mean if you try to turn on dry pavement with it in 4wd. it will bind because one tire is traveling a greater distance than the other on a turn. 4 low is for traction and torque when pulling a short distance. example would be pulling a heavy boat up a boat ramp or a steep hill,or pulling a tree stump out ect ect.

 

That's what I thought. I drove to and from work in a ft of semi plowed snow in 4 high at about 50 mph both ways.