Question about steering wheel shaking while driving

[Tommy]

I agree with Gary. I think it is more likely the unbalanced tire(s) at the front is out of sync with your front suspension components at some speeds and the shake comes and goes as those two resonant frequency patterns come and go into phase with each other.

[spdbrake]

Sean,

From your earlier posts (when you had 17" wheels) you've had this issue it appears back to 2017.

That said this thread may be of help if it's your pin drive hubs causing the issue.
BDR vibration issue finally fixed

[SBSerpent]

Originally Posted by Tommy

I agree with Gary. I think it is more likely the unbalanced tire(s) at the front is out of sync with your front suspension components at some speeds and the shake comes and goes as those two resonant frequency patterns come and go into phase with each other.

How would the front wheel go in and out of phase? If traveling in a straight line and with the same tire size and identical pressures in the front tires, wouldn't the front wheels (in theory) be rotating at the same speeds and as such, always be 'in synch' with each other? And, if the road surface is ideal with no bumps, ripples or undulations, then how do the suspension components go in and out of phase with the rotating wheels?

[eschaider]

Originally Posted by SBSerpent

How would the front wheel go in and out of phase? If traveling in a straight line and with the same tire size and identical pressures in the front tires, wouldn't the front wheels (in theory) be rotating at the same speeds and as such, always be 'in synch' with each other? And, if the road surface is ideal with no bumps, ripples or undulations, then how do the suspension components go in and out of phase with the rotating wheels?

The first time you turn a corner the inner wheel rotates slower than the outer wheel. This is why rear tires squeal when you use a locked rear axle on the street.

Ed

[Tommy]

Originally Posted by SBSerpent

How would the front wheel go in and out of phase? If traveling in a straight line and with the same tire size and identical pressures in the front tires, wouldn't the front wheels (in theory) be rotating at the same speeds and as such, always be 'in synch' with each other? And, if the road surface is ideal with no bumps, ripples or undulations, then how do the suspension components go in and out of phase with the rotating wheels?

I couldn't find a good picture to illustrate this concept so I'll try with words alone. All systems have a natural resonant vibration frequency. For a front suspension, that means that when the spring is compressed as it passes over a bump (or reacts to the up force from an out-of-balance tire), it will compress and then extended in predictable cycles until the damper (shock absorber) stops it. If you have an out-of-balance tire attached to that suspension, it too has a natural up and down motion (vibration) determined largely by the speed and diameter of the tire. Most of the time those two vibrations will not be in sync and tend to cancel each other out to a degree. But over time, the up motion of the tire will coincide with the rebound up motion of the suspension to produce a larger deflection of the suspension. The same occurs in the down direction. Such a phenomenon might account for your shake coming and going.

[SBSerpent]

Originally Posted by Tommy

I couldn't find a good picture to illustrate this concept so I'll try with words alone. All systems have a natural resonant vibration frequency. For a front suspension, that means that when the spring is compressed as it passes over a bump (or reacts to the up force from an out-of-balance tire), it will compress and then extended in predictable cycles until the damper (shock absorber) stops it. If you have an out-of-balance tire attached to that suspension, it too has a natural up and down motion (vibration) determined largely by the speed and diameter of the tire. Most of the time those two vibrations will not be in sync and tend to cancel each other out to a degree. But over time, the up motion of the tire will coincide with the rebound up motion of the suspension to produce a larger deflection of the suspension. The same occurs in the down direction. Such a phenomenon might account for your shake coming and going.

Shocks are the original Gabriels that came with the car (2011 build). Wonder if swapping out the shocks to the KYBs will help matters.