Steering Shakes like crazy!!
 

Hello everyone- looking for some help on an issue that I haven’t been able to find while searching the forum anywhere. I own a 97 Base with 77k miles. The steering wheel shakes like crazy. I went to have it looked at last week and the inside edge of the right rear tire was worn bald to the threads. Was told that was probably my issue. I changed all 4 tires at that point to brand new Firestone Firehawk Indy 500’s along with a complete balance and full alignment and went on my way. Felt much better...for about 30 miles! Now the wheel is shaking again. The faster I go, the faster it shakes. Has anyone seen anything similar and corrected it?? Any advice?? Thanks in advance!!!

It sounds like you lost a wheel weight. That’s what the tire installer uses to balance the wheels. Since it felt great for a time, and then you got the shaking again, I’m pretty sure it’s a weight.

Take it back to the tire place and have them fix it.

I would be curious to know why the rear tire was worn so unevenly... perhaps just an alignment problem, but the alignment person should have noticed and reported that if that was the case.

I was curious as well - he told me “probably just an alignment issue” which is what caused me to do the 4 wheel alignment.

It can be so much: alignment, bad tire, bent wheel, alignment, worn suspension, brakes, it goes on and on. An expert need to check it. Tire guys are rarely experts.

Thanks everyone- my last expert can’t find anything that would be causing it. I’ll keep looking.

So far I have:
Replaced tires with new
Balanced and aligned wheels
Had all wheels checked for cracks or dents - all good
Just changed brakes and rotors
Replaced rear struts

I know this seems like a wild goose chase and it’s driving me nuts (not to mention costing me money).

I’ll have the balance weights checked again. Maybe I lost one like racerboy suggested

front end shake
 

I thought of this post as I drove out of a parking garage and my front end had a bad shake that wasn't there on the drive to the garage. Upon inspection I found a stone in the outer tread of the left front tire, removed it and drove off with a smooth car. My guess is that you may have lost a weight since it cleared up after the tire change.

Sounds like a weight to me too unless you hit a large pothole and bent a rim or a belt slipped inside the tire, which is rare but can happen.

Thanks for the ideas guys! Definitely going to check the wheel weight like a few of you have suggested. It’s driving me batty!! So far (not necessarily because of the wheel shake but because the car just needed it) I have;
-Replaced all tires
-Had them all balanced
-Had an alignment performed
-Checked wheels, no dents, cracks or bends - new to me Kenesis wheels so had them checked prior to buying
-Replaced brakes and rotors
-Replaced rear struts

I’ll let you know if the wheel weight thing pans out

Thanks again

Thanks for the ideas guys! Definitely going to check the wheel weight like a few of you have suggested. It’s driving me batty!! So far (not necessarily because of the wheel shake but because the car just needed it) I have;
-Replaced all tires
-Had them all balanced
-Had an alignment performed
-Checked wheels, no dents, cracks or bends - new to me Kenesis wheels so had them checked prior to buying
-Replaced brakes and rotors
-Replaced rear struts

I’ll let you know if the wheel weight thing pans out

Thanks again

you've attended to the most common items without improvement.
I'd be willing to bet it's one of the items listed here:
https://www.pelicanparts.com/techarticles/Boxster_Tech/59-SUSPEN-Suspen_Overhaul/59-SUSPEN-Suspen_Overhaul.htm

I changed every front suspension component and the car is smooth now. It's expensive, but these cars are old and things wear out.

Thanks Jmitro - has the car back at the shop today and wheels were still in balance perfectly so it doesn’t look like I threw a weight like I was hoping.
Looks like I’m onto the front suspension.

Again - appreciate the help!

I agree with jmitro, sounds like a bushing issue. My buddy had the same thing on his e46. The lower control arm bushings were shot

How bout raising the car off all 4 wheels and doing a cursory check of all suspension and bearing components for yourself. Shake all four wheels up down sideways for slop and do visual checks. Tire shops aren’t Boxster experts. Check halfshafts, any wheel bearing, bushing play.

Gonna do that - thanks. Just found out a friend of mine has a great garage with a lift!

You have experienced the exact same problem that has been nagging me for the last 2 years.

Had wheels checked, straightened, re-finished, rod force balanced multiple times. New tires, and btw same as yours: Firestone Firehawk Indy 500s. Went back multiple times to the wheel/tire shop to complain. In the end, they told me the tires (new) required a borderline amount of balancing weights, and that I should put in a claim to Firestone... which I never did since I plan on burning them up next weekend at the track:D. Never again will I buy those tires.

Another issue to consider is "flat spotting". I've noticed this more on these Indy 500 tires, but I think all low profile tires flat spot to an extent. I noticed that in winter (cold) it does it more. Summer time (warm) less. I really annoys me because I spent so much time and money on my cars to get them to run well, and expect a nice smooth ride at high speed, especially from a Porsche.

The suspension bushings are known to be a potential cause of vibrations, but you would likely notice it more during braking only, especially in the front end bushings. I had that problem go away in my BMW 328. Worn bushings...

Thanks AZ - I’m going to try and get it up on the lift and dig into some suspension stuff this coming weekend. I’ll let you guys know if I find anything.

had same problem, was tie rods, can also be bent rim or uneven tire wear
especially front to rear ie: bald rears with new fronts,

FINALLY FIGURED IT OUT!!!!!!
Decided to change out rotors - thought maybe one was warped. Couldn’t believe what I found. The right rear hub flange was not allowing the rotor to “seat” correctly so it was cocked just a little bit. Took it off and checked the old one...same thing. Ground the edges of the flange just a touch, and the rotor sat perfectly. Shake is gone! Car is smooth as silk!!
So all the front end work, struts in front and rear, while needed - didn’t smooth out anything. Kept checking alignment, tire balance - would all be perfect but when wheels were put back on, that right rear would be cocked just that little bit and no one would think to check it. Thanks to everyone for all the advice and suggestions! If you’re one of the guys having the same issues - check your rotors and make sure they seat correctly

Modern Hi-Performance tires are not prone to belts slipping.


I'm guessing the alignment shop did not do a proper alignment, the 1st step is to inspect for excessively worn parts. Or the steering rack is loose etc.