Steering wheel shake / vibration at highway speeds ( 60 mph + )

[BoxsterInTheSun]

Happy Wednesday Boxster enthusiasts!

I've been slowly working my way through my new-to-me 2002 Boxster base model's eccentricities. I'm getting there, but next on my list ( and possibly one of the more annoying items ) is a steering wheel shake that appears over 60 mph. It's not "violent", but is pronounced enough that it ruins the driving experience at those speeds, and doesn't feel entirely safe.

Here's what I've done so far:

1) Checked that the air pressures are correct.

2) Had an alignment done. Made no difference at all.

3) Had all the wheels balanced at a shop that uses the road force balancing machine. This did improve the shake by about 50%.

My next focus is the tires, while they're in good condition and relatively new ( I think the previous owner probably put them on to sell the car ), they are pretty "cheap".

Front ( both sides ): Nexen N5000 PLUS 235 / 45 R17

Rear ( both sides ): Nexen N Priz AH8 235 / 45 R17

I'm wondering if rotating the wheels + tires will help me with my investigation into this issue. I was planning to take the rear wheels + tires and move them to the front ( rear passenger swapped with front passenger, rear driver swapped with front driver ) and see if anything changes.

Initially I was going to just go buy new tires and see if the problem resolved, but I'd rather not throw that much money into a guess. Will doing this rotation tell me anything? Or am I wasting my time doing it?

Thanks as always, you all are amazing and have already helped me take this car that I was ready to get rid of to something that I'm already really enjoying!

[Starter986]

Front to back. Vice-versa?

Likely you have a staggared setup... so that's not going to happen.

Me? I'm next taking it to a pro tire shop ) not a local independant (Joe's Tires) and having them perform a tire inspection.

How old are your tires? How are your wheel bearings? Did you try the 9/3... 12/6 method?

If evrything looked good... then I'm waiting on someone far more mechanically inclined than I to offer up some suspension diagnostics.

New tires might do the trick. Might.

Good luck. Report back... don't leave us hanging.

[Wret]

I experienced a similar issue: a persistent shake above 60 mph, peaking around 70 mph, accompanied by noticeable steering wheel oscillation. I had the balance of both front wheels checked twice, but no adjustments were required.

Assuming alignment was the next logical step, and given the advanced age of my front struts, I decided to replace the struts, bearings, and control arms before proceeding with an alignment. This improved the shaking by about 80%, and the noticeable oscillation disappeared.

When I switched to my winter wheels, the shaking stopped entirely.

Before spring, I plan to visit an alignment shop that offers a road force alignment test. This test can identify imbalances in the wheels and tires, potentially allowing the technician to "clock" the tire on the wheel to bring the imbalance within an acceptable range.

I’m also considering trying balance beads.

[azlvr]

Look for bent rims, that was my problem

[Danimal]

I’m in the same boat (think you may have seen my other post). Anyway I just ordered new control arms and tie rods front and rear. I figured if I have to do another alignment I’m going to do everything at once. I’ll let you know what I find. I’m pretty sure it’s my front lower control arms.

[BoxsterInTheSun]

Great questions. Let me try and answer them here...

Originally Posted by Starter986

Front to back. Vice-versa?

Likely you have a staggared setup... so that's not going to happen.

I was going to rotate them front to back. I'm not toally sure what a staggered setup is, but thought it would be possible as the tires are currently the exact same size on the front and the back, just different models of tire. I could easily be missing something though.

Originally Posted by Starter986

Me? I'm next taking it to a pro tire shop ) not a local independant (Joe's Tires) and having them perform a tire inspection.

In theory the shop that did the alignment and road force balancing was a pro tire shop, Wheelworks here in San Jose.

Originally Posted by Starter986

How old are your tires? How are your wheel bearings? Did you try the 9/3... 12/6 method?

Date stamp is 17th week of 2021, so under 4 years old and visually in great shape. I haven't tried the 9/3, 12/6 test so will look into that.

Originally Posted by azlvr

Look for bent rims, that was my problem

Is this something that can be done visually? Or needs to be done by a tire shop?

Originally Posted by Danimal

I’m in the same boat (think you may have seen my other post). Anyway I just ordered new control arms and tie rods front and rear. I figured if I have to do another alignment I’m going to do everything at once. I’ll let you know what I find. I’m pretty sure it’s my front lower control arms.

Thanks so much for the update, I'll be eagerly waiting to hear your results, I had considered this as a potential fix also. How much is that job going to run you in parts?

Thanks again everyone for the help!

[Gilles]

If you already tried all the suggestions, and still have slight vibrations, then my bet would be on worn struts..

[Dog'sLife]

Originally Posted by BoxsterInTheSun

Great questions. Let me try and answer them here...

I was going to rotate them front to back. I'm not toally sure what a staggered setup is, but thought it would be possible as the tires are currently the exact same size on the front and the back, just different models of tire. I could easily be missing something though.

The Boxster has different tire widths front and rear. The rear are much wider. If yours are not, that's a good starting point.

[Danimal]

More than I'd like to admit! I also ordered bearings, axle nuts, and swaybar bushings. I'm preparing for battle! When a Porsche shop wants $300 an hour to do anything, I'd rather just replace it for a couple hundred bucks and not leave it up to chance. Plus everything will be apart anyway.

Originally Posted by BoxsterInTheSun

Great questions. Let me try and answer them here...



I was going to rotate them front to back. I'm not toally sure what a staggered setup is, but thought it would be possible as the tires are currently the exact same size on the front and the back, just different models of tire. I could easily be missing something though.



In theory the shop that did the alignment and road force balancing was a pro tire shop, Wheelworks here in San Jose.



Date stamp is 17th week of 2021, so under 4 years old and visually in great shape. I haven't tried the 9/3, 12/6 test so will look into that.



Is this something that can be done visually? Or needs to be done by a tire shop?



Thanks so much for the update, I'll be eagerly waiting to hear your results, I had considered this as a potential fix also. How much is that job going to run you in parts?

Thanks again everyone for the help!

[BoxsterInTheSun]

@Danimal did you ever get to the bottom of this? I just replaced all 4 sway bar drop links ( they were all shot ), inner and outer tie rods on the front ( also shot ), and sway bar bushings front and rear ( you guessed it, shot ). Everything else looks good aside from the rear struts which are clearly leaking - I can't imagine they would be the source of a 70mph steering wheel shake though...

The search continues.