Vibration under seat at most speed

[arrrxivvv]

Thanks, perhaps I'll wait a while since the vibration is not yet too bad.

wheel bearings drone or hum.
friction noise, more likely to be the dust shield or brake shoe/pad clearance but you wouldn't feel it in the driver seat.
pain in the neck but you could reinstall the prop shaft to eliminate. or disconnect it to eliminate anything in the rear end.
or turn the radio up and wait til it becomes more obvious.

[arrrxivvv]

Thanks for the suggestions. Parking brakes have been replaced last year. The tire shop rotated the tire too.

Check your parking brake shoes have not delaminated and come loose. They will cause a vibration and dragging.

Have you tried a tire rotation to eliminate a bad tire or bent rim?

Neil.

[scot850]

If they rotated the tires and the shake is still through the seat, it is not the wheels or tires if you are not feeling it through the steering wheel too.

The parking brakes could still be the issue. A stuck parking brake cable, or a sticking rear caliper will also cause these issues. After you have driven the car, CAREFULLY!! touch the rear wheels near the center and feel if either hub is hot. Careful it can get really hot!!

Neil.

[arrrxivvv]

It's interesting to know about potential parking brakes issue. Just finished a drive, the rotors were warm but I was able to briefly touch them without burning myself.

If they rotated the tires and the shake is still through the seat, it is not the wheels or tires if you are not feeling it through the steering wheel too.

The parking brakes could still be the issue. A stuck parking brake cable, or a sticking rear caliper will also cause these issues. After you have driven the car, CAREFULLY!! touch the rear wheels near the center and feel if either hub is hot. Careful it can get really hot!!

Neil.