Is this normal? I've never had this with any other truck. If I'm stopped and I turn the wheel I get a shake in the steering wheel and you can feel it in the whole truck. It also seems to cause the ideal to jump a little. It's like the truck is fighting the tread to turn on the asphalt. I got a funny look from my wife when it did it yesterday. My tire size is 275-65-18. I don't know if that matters or not. My 02 F150 had 265-70-17's and it never did this. If I'm rolling even a little it doesn't do it. Is something wrong?

 

My 05 FX4 has started doing a similar thing lately. If i'm stopped and idling and turn the wheel, the steering wheel is hard to turn and vibrates. When it happens, the tach is usually hovering around 500 rpms when it does happen. If I accelerate and turn the wheel, everything seems to be normal. I have yet to take it to the dealer. I'm curious to know what it is too.

 

Not sure what is causing the shaking but when you turn your wheel the power steering puts a load on the engine so it is not unusual to see the engine speed drop a bit when the power steering is used at idle.

 

I get a little vibration turning froma stop sometimes when it's cold. Never thought much of it tho.

 

Think of it kinda like being in 4x4 and turning on dry pavement. The tires are held in place by the pavement and the brakes so they have to scrub. I bet if you put it in neutral and let off the brakes it would not do it or would be slightly noticeable. When you speed up the engine you increase the available pressure to the steering ram is the reason it doesn't seem to happen above an idle. Your idle may be a little low but, that's what it sounds like to me.

I have the same thing happen to me with another brand of truck (usually when I am trying to hook up a trailer).

I am no expert just my .02 worth.