2003 bonneville vibrates on highway speeds

[Mckinney]

As the title says, it vibrates on the highway from 55-70+ , the tires are brand new just got them today from discount tire , it vibrated before but i thought getting brand new tires would help, any advice would be great, also the car was aligned recently as well

[96 SSEi]

hi, were the tires balanced to 0? check to see if the weights are in place also

[Mckinney]

Yeah they were properly balanced ,and they all have weights

[PilotScott]

Sometimes a RoadForce balance will help. It's a common issue on Bonnie's of our generation. Outside of tires it could be a suspension issue, but a vibration at hwy speeds won't be an alignment issue.

[Mckinney]

What is a roadforce balance? And thats what im thinking where should i start? I replaced the right side control arm and both tie rod ends, the left side needs to be replaced and my sway bar bushing on the left side is shot, would this be the problem?

[MKMike]

I replaced the right side control arm and both tie rod ends, the left side needs to be replaced and my sway bar bushing on the left side is shot, would this be the problem?

Yes.

[Mckinney]

I noticed the problem at low speeds also around 20-30

[nos4blood70]

Left side control arm could definitely contribute to this issue if it is known to be shot.

[Mckinney]

Got it, ill do that soon feels kinda like there is a bubble in the tire but they are brand new from sat

[PilotScott]

If the control arm needs replacing I would definitely do that first. Depending on the reason for replacement (ball joint or bushing) it can cause all sorts of issues, now and in the future. Hopefully the tire doesn't have a slipped belt, it seems rare these days unless it wasn't good quality to start with. The tire shop you got them from should check them back out.

A RoadForce balance is a type of balance that uses a textured drum and higher rotational speeds than your typical balance job. You can call around to different shops; my previous shop had one. It wasn't done very often as most ppl seem to expect some vibration at highway speeds just due to tires, road conditions, weight distribution, suspension, tire inflation, wind.....but it is a good option to explore to dbl check and give you some peace of mind.

[maxi426]

Low speed sounds like tire or wheel. The Roadforce balancer would find that easily. Id think the first thing would be to get back to the tire store, and have them get the car up on the lift to look for a bent rim or out of round tire. If noting is apparent there, start moving the tires front to rear two at a time to see if the vibration seems to change.

[PilotScott]

Over-diagnostic has sometimes been an issue of mine ...Rotating the tires would help pinpoint a tire issue over suspension.

[AJT2004]

Vibration issues can be difficult to diagnose. In addition to the other good suggestions, check your front brake rotors. Sometimes badly corroded rotors can cause vibration issues as well.

[dougtoth]

I would also check the front rotors.
I had some that were warped (from the heat) that caused a vibration.
Replaced rotors and vibration went away.