I have a 2000 F-150 S/C 4x4, automatic.

My wife and I were on a road trip last weekend and I noticed that occasionally at lower highway speeds (60 -80 KPH) I get a slight vibration through the truck. At first I though I was running over "Wake-Up" strips on the road but when it happened I could see nothing on the road. When we got nearer to home I noticed it on roads I travel frequently where there usually is no vibration.
It does not last long..less than a second, and feels like I'm running over a cattleguard or something. The truck is running fine otherwise...tranny fluid is good, no vibration through the steering wheel (ie not a tire balance problem). Can anyone help me with this????

Thanks,
Chris

 

Could be a lot of things. Best thing would be to get up in the air and have a look see. Tires is first thing that comes to mind.
I have had cars with tires that belts went bad on. Check also for out of round tires and bent rims.
Tranny shudder in OD?
Tie rod ends?
How about a hunk of mud/clay stuck to inside of wheel?
U joints starting to go?
Wheel bearings?
If a shock is starting to go I could see where you may get a vibration. One of my front hd oem on my '01 Scab 2wd started leaking at 12k.

Somebody else will be along shortly with more suggestions. I know next to nothing about front axles on 4wd.

 

Thanks for the suggestions.

I don't think it's tire or worn parts though b/c it's not a predictable occurrence apart from happening at around 60 - 80 Km/H. What I mean is every time I accelerate through the 60 - 80 Km/H range it doesn't happen..only sometimes...it's really weird.
The truck only has 68,000 kilometers on it.

I saw another post that suggested to someone that a bad torque converter sometimes feels like driving over a light washboard (that's what this feels like) and it's audible too, you can feel and hear the vibration when it happens.

It's going into Ford on Saturday morning for a test drive with a mechanic but I appreciate all suggestions in the meantime...thanks.

 

It's TCC shudder.

The torque converter is locking and unlocking repeatedly... Multiple times every second. Overheated or old fluid can cause this. If you do an internet search under torque converter shudder, you can find a technical explaination of what's happening.