Strange vibration occurs briefly at high speeds
 

Yo --

Alright, so if the 7 doesn't see much highway driving for an extended period of time (say, a week or longer), the next time I take it out on the highway it gets this nasty vibration -- it starts around 55 mph. It sounds like it's coming from the rear passenger tire. (By the way, all new tires installed <500 miles ago.)

I'd assume it's the U joints or something related, but the odd thing is, it only happens for 30 seconds ~ 2 minutes. After that, it totally stops, everything is fine and smooth. It happened today as I went to my hockey game, but it didn't happen on the way back.

Any ideas whats causing this and why it acts like it does?

Thanks guys.

that happens to wheels when they are not balanced prop. or poss. mmisalignment of veh. I had this prob. on my suv when i had the 22's on it.. took it to my shop and the wheels werent' balanced correctly!-Erik

did you experience any power loss when it was vibrating?

what kind of vibration are you talking about here.....

was it major, like it shook the back end?
or subtle like a wheel bearing noise?

No noticeable power loss, but I'm not exactly going to slam the throttle when the rear is shaking.

It's definitely a noticeable shaking coming from the drivers side rear, not subtle by any means.

I have a similar (if not identical problem). It gets worse when I brake. However, when I break, it seems to go away quicker.

I got new tires about 800 miles ago that should be balanced/rotated. My alignment seems to be good, although I should do it anyways.

Update: I took the car to the shop to have them balance the suspect tire (the sound had been coming from the driver's side rear).

They balanced all four tires, free of charge -- which I assumed meant that the tire wasn't unbalanced (is it possible for them to spot an unbalanced tire??).

Anyhow, got on the highway to test it out, and sure enough, there it is again. This time it feels like it's coming from the front driver's side wheel. Also, the car was pulling noticeably to the right. When the sound started happening, it would vibrate worse if I had to turn against the tendency to drift right. Similarly if the road lulled to the right, then the noise would stop as the car pulled in the direction it wanted to go.

The sound stopped after about five minutes. And again, on my way home later that night, it didn't happen.

I need more input. Does this sound like an alignment issue? I don't wanna drop the cash if it doesn't solve the problem. Also, about how much am I looking to pay for an alignment? Thanks again.

Since you say the vibration seemed to move from one wheel to a different wheel after the re-balancing, it is probably related to a "bad" wheel/tire. First check the tire pressures and lug nuts. If both are OK, find a shop (www.GSP9700.com) with a Hunter GSP9700 balancing machine and take it to them for diagnosis. This is a vunder machine that can spot things like out-of-round tires, bent rims and so on.

Yes, it sounds like an alignment issue to me, a setting somewhere is off (I believe the term is toe out on one side) and causing it, the vibration is probbaly your new tires skipping across the road as you said it smooths out if you point it towards the direction.

i had this problem in my car,it may be a broke belt,sure theyre new tires,but take them off and look at them,it may be a horizontal or laterral belt that snapped,,i have thsi happen wayy to often in my caprice calssic(what do you get when i drift 2 1/2 tons of tank) but ya ..look that over