I'd take a close look at the tires look for cupping or if you have those goodyears on they cause vibrations. I like the bf goodrich raidailtrails better My wifes expdetion rode like junk untill we changed the tires.

 

thanks for all the replies. sorry, i was gone all weekend.

-I have the Goodyear Wrangler AT/S on it. I took a look at them over the weekend and they're getting a little balled on the outside edge, but they still have a good amount of tread on them (maybe 45%). I just drove it 280 miles today and only noticed the problem between 40-45mph. The steering wheel didn't shake at all. It's just the whole truck shaking, i don't know how else to describe it. I'll be taking it in to Ford this wednesday to have it looked at (along with a few other things). If the tires turn out to the the problem, then this is a damn good excuse for some BFGs

-i looked in the serivice manual today and it said that tranny fluid should be changed at 42K miles. I have 46K now. It had 45.5K when i bought it. There's no records in there of when any service was done on it, so i have no idea if the tranny fluids been changed. I looked at the dip stick this mornning for the tranny and it was a dull red, almost pinkish color. I don't know how dirty tranny fluid would get, or what that color means.

-also gotta get the power steering pump looked at. I got that infamous power steering whine

-thanks for your help guys

 

Sounds like the exact same problem I had, and it took Ford 4 or 5 tries to get it figure it out. The whole truck seemed to shake between 40 and 45 and it didn't matter if it was in drive or nuetral, speeding up, slowing down, or drving steady. And it didn't matter which tires were on front or the rear.

Do this little test before you take it to Ford:
Jack the truck up (use safety stands), start the engine and put it in gear. Get out and look at the tires from the side. you'll have to use a piece of the frame as a reference point. watch to see if the tire turns smoothly against this reference point or if it 'hops'.
If you don't have 4wd, have someone spin the front tires while you watch.

 

From what you describe, I can pretty much guarentee that it is the torque converter shudder. I had the same exact problem about 2 months ago on my 97 s/c 4x4 4.6 with 43000 miles. It felt like rumble strips. All you need to do is get your tranny serviced (change the automatic transmission fluid - including draining the torque converter and replace the filter.) This ran $200 at the local Ford dealer. The truck hasn't done it once since then.

 

yes, thats exactly what the guy in the service dept. said.

i called them today to set up an appointment, and i told him what it was doing and what it felt like and he said they call it "rumble strips". So, on wednesday, we'll see.

 

Dealer never did find problem, swapping driveshaft, balancing tires etc After about a month of trial amnd error they improved it some. After I replaced tires it went away completly.

 

In my case, it is not the tranny. Problem started around the 3,000 mile mark(no accidents..was not driven hard either). I drained the entire tranny and torque converter and installed a new filter at 10,000 miles. Tranny fluid is right where it should be also. I feel my vibration in the seat of my pants only..nothing in the steering wheel...nothing on the floor. Passengers do not feel it at all when riding up front. Right at 62 mph through 66 is the only time I feel it. It feels like the drivers side rear is the problem. I have already rotated the tires...no luck.

Another thing....truck seems to want to pull to the right when the steering wheel is centered., going above 40 mph. I just had the front end aligned by one of the top shops in town...and that did not help much.

It is either the tires or a bad set of rotors....or both. Even though it is not that bad..and not an emergency at all....I might just take it in and have it looked at under warranty
.

 

I don't think it's a real bad problem either, but i'd like to get it taken care of while it's still under warranty. the warranty runs out in 2 months, so its better i get it done now.

 

UPDATE: I took her into the dealer yesterday to get the tranny looked and and serviced. Well, the guy says that it's normal. I was like WTF??!! that shaking if normal? Regardless, they did't fix it and it still shakes. makes me mad too because it's still under warranty and they won't fix it. i don't want to have to wait until the warranty runs out and then pay for the fluid to do it myself. I heard the fluid is like $166 for 16 quarts

I had them look at the power steering pump because it whines and they said that was normal too

-well, i'll keep trying.

 

Hey Dan. At first the dealer told me that it was normal too. I made a tech go for a ride with me and when it shuddered, I said does that feel normal to you? He agreed it was a problem when he was confronted with it. My truck was also under a used car warranty, but they wouldn't cover the tranny service. I fought with the used car manager and he agreed to split the cost with me.

As far as the power steering pump goes, that is pretty typical of all Ford vehicles. I don't even notice it anymore.

 

I got 4 new tires this weekend, and still have the same vibration between 40 and 45mph. I'll be callling the dealer in a few minutes to schedule an appt to have the torque converter problem looked at.

Anybody willing to bet they'll fight me about changing the tranny fluid since I have almost 28k mi on it, and the manual calls for changing the tranny fluid at 30k mi? I hope not since this has been a documented problem since truck was 6 months old and their is a TSB for it!

 

I'm not due for a new set of tires for a while. At least until the summer.

I wonder if the truck wasn't under warranty, would they have gone ahead and changed the fluid? Probably, because it would have been at my cost. Weird thing is, I didnt notice the problem at all the morning i took it to the dealer for service. I haven't noticed that much at all anymore either. Weird.