Let me just start and say thanks for everyone taking the time to look at this. Here is my problem, I have a 2003 SD 7.3 Diesel with 77k on it. In the last 200 miles I've developed a vibration, rather strong that seems to be stemming from the bottom of the truck and working its way upward. The vibration is rather odd, because it only starts when I drive the truck between the mileage of 35-50mph. I thought maybe my tires were going bad or maybe they were out of alignment. So I had them replaced with four new tires, but the problem still persists.
Has anyone else come across the same problem or least point me what I need to look for? If you need more information, please ask and I will do my best to answer them. I just want to get this work horse up and running proper.
Thanks!

 

have the same issue. have been living wiht it for 10 months now.

1st place everyone here will point ya is to the rotors. not saying this is NOT your issue but it wasn't mine. I'm leaning towards the u joints now.

I have replaced just about everything there is to replace.
and to answer your Q. no the u joints dont look or feel bad

 

Have you checked the u-joints on the driveline(s) yet?

 

why would you point to the rotors? If it were the rotors would it not effect the truck at all speed and not a dedicated zone?

 

I would look at the u-joints and then then the center support bearing ( carrier bearing ) in the drive line.

 

Same problem here but it's worst when you have a load on. Uncle said with his it was the carrier bearing.

 

Had same problem on my 2003 F250 5.4. really bad between 40 and 60 mph. 70,000 miles on truck. I had a bad u-joint and the splines where the two drive shafts come together had a little play in them.

 

x4 on the u joints. look real hard on the inside of th joint itself. see if there is any wear on the inside of the elbows there. mine went out and after searching it turned out to be the bearings burning up and turning to dirt. this will cause a little off-balance on the rotation of the driveshaft itself causing the vibration. i would start there at least. good luck

 

The rotors could cause a shake at only a certain speed. Mine was 65 to 70, how convient since a drive alot of interstate, but I had a suspicion it was the rotors and was right. Main reason I changed them first was because I could also feel it in my brake pedal sometimes when I really got on the brakes hard. Just a suggestion you might try gettin on the brakes hard and see if you feel anything. It's kind of a push back against your foot repeatedly. Don't mistake it for the grind feeling your ABS can make. ? maybe that will help.

 

thanks for all the replies! So far this I what I've done so far as per a couple of your suggestions I looked at the brakes and ended up replacing rotors and pads, new tire on all four wheels and balanced. Looked at the ball joints and seem to be ok. The vibration is still there and no improvement. Since I'm under qualified to handle this. I have another mechanic coming to take a look at this and see if we can find it

 

U-joints, not ball joints!

 

Have the same problem (which started recently) on my 2003 F350 as Carbon Clear. Did replaceing the u-joints solve the vibration problem? My brakes are almost new and the tires in front are new. Thanks Mike F.

 

Mechanic found two bad u-joints, So I had all of them replaced along with the center support bearing. Thanks for all the info!