Have had a small vibration at speeds of 60 mph. I put on new tires and had an alignment done but it is still there.

Could this be an imbalance in a driveshaft?

 

Could be, yes. Was it there before the new tires and alignment?

 

Yep It seems less though and the alignment shop said it was way out of whack. The vibration is not in the steering wheel. The passenger seat just wiggles a little.

 

Has the original front prop shaft been replaced or rebuilt? If not, do that asap. Like before you drive it anymore.

Also check the the u-joint on the rear and inspect the rotoflex coupling at the rear diff.

 

Old rule of thumb...

If you feel it in the steering wheel...usually an issue in the front end components.

If you feel it in your seat...it's usually in the drivetrain.

Since you feel more of it in your seat, I'd check the rear shaft and joints.

Side note:

My wife complained about a vibration in the front of our 03, so I went to take it to work to check it out...never got that far. Vibration was to worrisome (pictured having to replace "another" trans), so turned for home. Jacked it up and all I could find was the weight missing on the front driveshaft (which was about two 2" by 2" in size). Haven't had a chance to remove or have balanced yet...but everything else seemed okay. Hopefully within a week or so I get that done.

Brian.

 

Hi, could be wheel balance if in the steering or shaft balance or UJ's knacked. Alternatively engine and autobox mounts create vibes. Also check the steering rod ends for play as they can create weird vibes at some speeds.