Shaking over 70 mph, soooo confused
 

As the title says, my 986 1997 shakes like it needs a balance over 70 mph. I have had all 4 wheels balanced numerous times and rechecked more. Tire pressures are the same and good...I don't know what it could be. It's deffinately not the engine or trans. Steeringwheel shakes and car occasionally shakes. Gets progressive with more speed. Should I try another balance shop?

You should also check...
 

... the tire's tread.
It could have a bulge or the wheel could be damaged.
Happy Boxstering,
Pedro

I hear you. I had to have my tires balanced three times before they actually got it right.

The last time I asked the manager to tell the tech to spend an extra minute and be sure that he got the balance right for high speed running.

Also be sure and ask for them to use the glue on weights that balance the wheel in two axis (axes?) and not the cheap crimp on weight on the inner wheel lip.

I have the same problem and am looking for answers. I need to have a rebalance done asap as this 70mph shimmy bugs me like crazy.

Let your fingers do the walking & call the shop first & ask if they will do a " dual plane backside dynamic balance to 1 gram tolerance with stickon weights" if they can't or won't keep searching.

Is the car modified at all? I chased a similar issue that turned out to be lower quality front spacers. Even after balancing the problem remained. I will only use H&R's now, lesson learned. I also noticed some vibration at freeway speeds before I replaced frt engine mount, but that won't cause steering wheel to shake. Just FYI.

Thanks byprodriver. I will call around. Is this type of setup familiar to shops?

Tread is good and no bulge. I can't believe how many others have this problem!!! It sucks ;). I'm going to try a more well known tire place and let you all know.

With the current trend of hiring cheap inexperienced labor maybe not, but should be part of balancing 101. Dynamic balancing measures lateral or side to side balance as well as static or up & down balance & is indicated by having weights on inner & outer edge of the wheel. Backside means all weights are positioned behind the "face" of the wheel.

check your suspension , something might be worn out.

Perhaps try a Road force balance on a Hunter GSP9700...

It's possible, but I wouldn't know which component to check...any advice on what part of the suspension would cause my problem?

it happened to me before when i drove at 90km/hr+... i tried over 230km/hrs and felt like i'm driving a boat on a lake.

I had this bad experience after i installed a replica wheels.
you can try to ask the shop to do wheel/tyre alignment with a tools that looks exactly u put on your car with 5 screws on. (don't use the center cap hole for wheel/tyre alignment)

If this problem keeps coming out, try to change your wheel and test again.

in my case, i finally install an original 18" wheel from 987.

Just set up a road force balance with my local shop.

Checking for worn components is easy, jack the wheels one at a time (unless you have a lift) check for play at 12&6 and then 3&9

Good deal, these usually seem to help a lot. Hope this works for you!

might want to also loosen all the lugs and tighten criss-cross at 20lb intervals. I had a similar problem last year, and it seems to have been the difference with mine. ymmv

man was there a time when I needed these words ready to roll of my tongue!

Hmmm, voice of experience? ;)
I saw your pictures on your site... :D I'm hoping to join you one of these years!

I do hope the balancing takes care of it, though.

UPDATE : Car has been at a Road Force shop with the proper gear and its NOT the what we thought:confused:. Looks like the tires might be the culprit as previously mentioned. Shop said that Heavy "V" directional tires might be to blame. Has anybody heard this before? They are going to put 2 tires on the front and we are going to give that a go and see if it works:). If so I will update.

Current tires are have a very aggressive V pattern now so I am having shop place a good low pro non directional tire on to see how that improves the "SHAKES".

I had a very similar problem recently. I replaced the inner tie rod and it was fixed. No more shaking or feeling of imbalance at 70mph+.

Thanks projectm96 for that info. I had all that checked so we will see what happens with the new tires. Waiting for the call now. :)

Tires tires tires
 

Well, just came back from the shop and after 6 months of vibrations at 68-70+ mph I have finally removed the shake from my car. Called around for a shop that does the Road Force work as previously recommended and found that my local shop has one. Scheduled the appt and took the car in today. They put the car up on the lift and inspected all the suspension/bushings and bearings then got to work on the wheels. Wheels were fine too. Tires were getting choppy on the inside (from the vibration of course) so the shop called me and we tried another set of Federal tires (what I had on it already). Guess what ?? Same problem. So we tried a set of Michelin Pilots on the front only and the shop called me down for another ride and BINGO. Car now rides like it should. Two new fronts on now and the rears are on the way (on order).

Took car up and down the expressway from 60-85 with NO VIBRATION at all. Its the real deal. Now I cant wait to go on a road trip.

Thanks to all for the help.

:D:D

Check over on the general discussions section and do a search for "tire problems".
I posted a similar problem recently and chased the monkey for 4 months. I was just about to buy new rims for the front (tire place told me I had bent rims) when I took the car to a tire store with a road force balancer. They gave me back my car in less than an hour and it ran really smooth. The also found a new tire on the rear that had a high spot in it (Michelin Pilot Sports). Replaced and now all the vibration is gone. Drives smooth as silk.
P.S. I ask the guy who did the balance what he did to make the shakes go away. He just smiled at me and said "I'm just damn good at what I do". End of questions. I just drove it home with a big smile on my face.

FT 52 - Thats basically the same response I had today. I told them I wouldnt pay until they could find the problem. He said it was simple, I noticed you had cheap directional tires and after inspecting all the suspension components it was a simple solution - put some good tires on and check it out. By checking it out he made me take him on the highway to 85-90 with NO VIBES. Thats one confident guy. :)

FullThrottle - forgot to say to be safe. Your in KY right? Hope your safe from the storms.

We had to hunker down in a basement today for about 2 hours. 15 miles north of us got hit pretty bad. Whole town pretty much wiped out. Worst of the storms went just north of us in Southern Indiana and another bad cell went about 20 miles south. We were very lucky that Louisville did not take a direct hit.
Did get pretty hairy though.

Thanks for asking.

P.S. I'm glad you solved your problems. I will only put OEM tires on from now on. Cheap tires will cost you in the long run.

Take it to your Porsche dealer for the balancing and alignment check up. I had a bad experience with this problem. I went to STS since I needed tires on a Saturday he sold me Kuhmos' What a disaster that turned out to be. Once I got on the highway the car was shaking like it was coming apart. I bring it back for adjustment and again the same problem. I went to my dealer and I asked to take a look at the problem. The culprit was that STS used the wrong weights and installed them in the wrong location. Last time ever I took my car for alignment to anyone other than Porsche.

I skimmed the post but did not see the word alignment. Is the car properly set up with an aligment. ? My car had this when I bought it and it needed new tires and the ALIGNMENT was what fixed it. Bob

Motobob, I think most have had the alignment done as a first step but this shake still continued. It was not a low speed shake as in several of the cases here. Mine (and a few others on here) had shaking at 67-70mph then it got progressively worse. Bad TIRES were the culprit for me. It was the last thing for me to try (since it was the most expensive) without replacing suspension components.

I see I skimmed too lightly; :-) glad your problem was fixed. New Tires were the answer for me as well in 2008. Bob

STILL HAVE THE PROBLEM

Well, i looked at my suspension and saw that the right side was pretty well worn out (car was in a small accident and all suspension on right front was replaced with used parts)...they must have found a high mileage 986 to take from : /. So, i began the fixing. I replaced the wishbone and trac bar. New inner tie rod end is on its way as i noticed they didn't change the inner tie rod (its a little bent). Took strut out and tested it, its working great. Could the inner tie rod that be the sole problem? I don't know how it could as its not a spinning part, only controls turning. UGH...headache to say the least.

Don't reply telling me to contact the shop it was done at, trust me, i want nothing to do with them whatsoever.

ALSO- i put new rotors on the front recently (post shaking problem) and noticed it got worse. I looked at the rotors and noticed they don't line up perfectly (to the naked eye) to the hub. It seems the recessed, tapered, screw holes aren't perfect.

DOES ANYONE DO OR SELL HONEST WORK OR PARTS ANYMORE!?

Fixed!!!!
It had nothing to do with the rotors that I was complaining about in my last post. I replaced the wishbone, control arm, and inner tie rod. Then took it to a very highly recommended shop and had them change the rear tires and balance/4-wheel alignment. It drives like new!

As Pedro brought up in the beginning, the tires were PART of the problem. Rears were very very worn on the inside, which caused some o the car vibration. The rest...I'll never know exactly as I replaced almost everything up front :).

Nice. Now we are both ready to ROLL. Glad you fixed it. Interesting that we both had similar issues/shaking concerns and different solutions but the SAME result. Go figure.

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I checked that on mine madmods. Cleaned everything while it was apart. Scrubbed and cleaned the inside of each wheel as well so now there as shiny on the inside as they are on the outside. :cool:

Take the wheels back off.. and tape the weights on. 99% of the tire places out there spend 3sec cleaning the spot where they install the sticky weight. Tape them on (unless you keep your wheels spotless and the tire guy didn't have to clean) << not likely

We use a silver metal tape :)

Glad to hear Louisville is ok. My grandparents lived their, and we had a family farm in Eminence for nearly 100 years.



B

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