Hey guys im new to the forums and hoping you guys can give me some insight. I have an 03 expedition that i just rolled 132k miles on the other day. When driving around the city she drives great but the highway is a different story. When driving around 70 to 80 it seems to pick up a vibration that seems almost harmonic in nature. Its not very intense but definitely noticeable when paying attention to it. I've replaced just about every front end component including the steering rack, inner and outer tie rods, idler arms, upper and lower ball joints/control arm on the uppers. Would love to get her to drive like new, so any ideas?? maybe bearing or cv joints?? I also had the tires balanced at discount tire co and that didn't help the problem

 

The drive shaft u-joints would've been the first thing I addressed.

 

I have never done u joints before. Is this an extensive job that needs to be done in a shop or is it something that i can handle on my own. If its something that i can handle myself any info about the job would b great. Thanks for the quick response btw

 

If you've never done them, or don't have access to at least a 12-ton press, then I'd let a shop do them. The front of the drive shaft has a double cardan joint and can be very tricky to do.

 

Just to be sure before i go to the shop to have this done, is there anyway i can check for play in it?

 

Do you have a bug deflector or any dents ? You could be having an aerodynamic fluctuation.

 

nope no deflector or dents. All the body panels are in pretty good shape. I also have the stock 17 inch rims in good condition so i dont think any problems are coming from these aspects.

 

Set the e-brake, chock the wheels, shift into neutral (engine off.) Then go under the truck and try to pry the two halves of each joint in several different directions to see if there is any play. There should not be any play.

 

Is the vibration in the seat or the steering wheel ? From what I gather from you changing out all those front end parts i'm assuming the steering wheel. A driveshaft vibration you would feel it in the seat or your feet.
Have you checked your bearings?

 

The front end parts were all done about 5k miles ago as to a shimmy in the steering wheel. Replacing those took care of the steering wheel shimmy however the vibration on the highway has only been around for about the past 2k miles and that can be felt in the seat. I checked the bearings last time i had the car up on stands by grabbing the sides of the tire and checking for play.They seemed to be fine but im not sure how accurate of a test that is to check them.

 

I think im going to go ahead and change the u joints. can anyone provide me with the part numbers of the u joints for the front and rear drive shaft?

 

have you got any update on the vibration?