High Speed Vibration

My 2003 Buick LeSabre with 66,000 miles has begun to vibrate somewhat noticably around 70 MPH. It does not vibrate at speeds lower than 65 MPH signifigantly, and is not detectable at all under 60 MPH. I would like this vibration to go away because it is a bit annoying, but also because I fear it may be damaging other parts of the car. The vibration is most detecable comming through the steering wheel. Any ideas?

Could be simply a tire that need balancing, but if the tires are near their end of service life, you could have a belt in one of the front tires that has become de-laminated in parts and is shimmying. New tires will take care of that. Other possibilities are a bent rim, out of balance front axle or a missing damper off one of the front axles. You should not have worn wheel bearings or CV joints at this time unless you kicked up a piece of debris that cut the boot on one of the CV joints, but you could have that looked at just in case.

I agree with Keith and he has hit on most of the likely problems. One way of reducing the possibilities is to rotate the wheels from the front to the back. If the problem does not change it is likely not a tyre or wheel problem. If it does, you know it is a tyre or wheel problem.

did you recently rotate your tires? an out of balance tire moved from the rear to the front will cause the same problem…

Jack up one side of the front end. With hands placed on each side behind the first wheels tire, pull back and forth, side to side (horizontally) with each hand. If it feels loose, then note it. Then do the same thing vertically to that wheel, and note that. Then switch to the opposite wheel and perform the same two tasks and note any looseness. Any major auto parts chains will be able to tell you which parts need replacing based on your results. You can then have a mechanic install those parts. Some major repair chains will check all this stuff for free and install the correct parts at a fair price. In my opinion, you should not be paying more than $300 to fix this unless theres severe damage.

Also, Ive experienced the same symptom in another model buick and it ended up being a bearing on the where the axle connects to the transmission, and that could be quite expensive to replace.

Thanks so much for the info.

The car still has the original factory tires on it, so I think they need to be replaced, and they do have some sideways/cross wear on them, but the treads are more than 16th of an inch so I figured they are okay. It is strange to me that only at speeds > 65 MPH it vibrates or shimmys noticably. I think that I will do a tire change and alignment and ask the mechancis to look at all the parts you mentioned. I will report back when done. Thanks again!