996 steering wheels shaking even after tire balancing: SOLVED !

The steering of my 2003 Porsche 911/996 was shaking a bit at speed above 60MPH. I went to get the four tire balanced on a proper Hunter Road force machine. But even after that, I can still feel the steering wheel shaking. It shakes pretty much all the time. The only pattern I 'think' I observe is that when I start the car, the first miles are usually shake free. Then after a while, even at same speed, the shaking comes back. The steering shaking is bearable, but annoying for a car that is supposed to give great steering feel. The tires, front and back, have good thread on them. The front are 225x40x18 and rear 295x18, mounted on stock Porsche wheels (turbo II look). Stock suspensions. The car steer to the right a bit, but I was told the alignment would not generate shaking in the steering.. Anyways tomorrow I bring the car to the shop for an alignment may be they'll find something. I wonder if some screw on the steering rack is not loose or something like that.. Anyone experienced something like that ?

If you have spacers, that's the culprit. Get hubcentric and you should be fine. -td

Something similar happened to me last Summer. Bought new tires, had them mounted (the car was driving A-OK prior) and noticed a vibration in the right front. The place I went to had a bunch of kids using old equipment. I told them I need a 'better than good' balance. It was cheap and that's what I deserved. So I took the car down the road to a brand new Tire Barn. They had all the high tech machines. They told me (and proved) that my right front wheel had a bend in it. Not good news. They said they needed to balance the tire on the wheel by matching the wheel up with the tire. Not exactly sure what it meant but the car drove great afterwards. So maybe you have a bent wheel?? Hope this helped.....

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Have experienced nothing like this with my 996 but once in a great while with my 02 Boxster I have. Vague sort of shimmy/vibration appears with tires up to temp while traveling down otherwise smooth roads at highway or freeway speeds. Since I always use N-rated tires, have the tires/wheels load force balanced and keep the alignment spot on spec, I was puzzled at first but traced it the front tires being overinflated by some amount. Not much, on the order of a few psi over the cold 29 psi. I had been experiementing with different tire pressures -- running the tires a few psi over the recommended cold psi (probably to see if I could notice an improvement in gas mileage) -- and a sudden warm up caught me and the car with tires over-inflated for the warmer weather. Roughly tire pressure increases 1 psi for every 10 degrees (F) increase in ambient temperature. Tires properly inflated for say 45F will when a warm up has the ambient temperature rising to 65F be over inflated a few psi. If the tires already a bit over inflated... With a quality tire pressure gage check the tire pressures with the car and tires cold. The morning after the car has sat unused all night is when I like to check tire pressures. FYI: For best alignment result, have tires inflated properly, gas tank full, spare tire and tool kit (if car came with these) properly installed and car empty of any weight adding "junk". FWIW: Some indy and Porsche alignmment techs like to add "ballast" to driver's seat or floor board to compensate for the driver. I have had my Boxster aligned both this way and sans any weight and could not tell the difference. My opinion is it doesn't matter. What does matter is the quality of the alignment. I like to get a before and after printout to study see what settings were off and by how much and what the new settings were. The few times -- well at least once I remember clearly -- I failed to get this later I found out the alignment (done at a dealer too) incorrect and the sub standard alignment cost me a new pair of rear tires that wore out before their time as a result. Sincerely, Macster.

Might see if you can get the tires road force balanced. Not all shops will have the machine to do it.

I have tried to lower the pressure, it doesn't make a difference. The wheels where balance on a GSP9700 hunter road force, which does apply force on the wheel while balanced. It is either the alignment or something loose in the steering, but at slow speed it is absolutely sharp, so I hope it is the alignment. I'll keep you posted.

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My previous post was not intended to get you drop the air presssure below the recomended setting, only to check tire pressures were correct. Too low a pressure will cause the tires to be more active and wiggle possibly shimmy or even mimic an out of balance condition. The tire pressure wants to be pretty close to if not at the recommended amount for that size of tire. The correct inflation pressure listed on the inside of the gas cap cover lid or in the glove box or somewhere. What brand of tires are you running? How many miles have they accumulated? Tires vary in quality and you might have a bad set or just a bad tire, sometimes bad from new, sometimes going bad after accumulating some miles. One possible indication a tire bad, or even a wheel bad (see below) is the amount of out of balance the tire/wheel assembly has. We never think of this until after, but if you have reason to have the tires balanced again ask tire tech to write down the amount of out of balance and advise you how these numbers compare to what the tire balance maker provides. Also, one person was reporting a bad balance symptom and the cause traced to a noticable "flat spot" in the wheel's rim where the wheel hit something hard enough to bend it. I don't know the history of the car and its type of usage but if you can with the car safely in the air with its wheels/tires able to spin you turn be hand each wheel/tire assembly and carefully look at the tire tread face, tire sidewalls, both outside and inside, and at the outer and inner wheel rim diameters looking for any runout either radial or axial in nature to verify each tire and wheel at least rotate with no obvious signs of out of roundness. Sincerely, Macster.

I am running Michelin Pilot sport with 5000 miles on them, +-50% thread left on them. The person who balanced the tires looked at the wheels for possible damade but I admit they did not spend enough time to really be sure 100% the wheels were ok. The best would be to have a set of wheel to make a switch, I'll see if that is possible tomorrow at the shop. Is there anything onthe steering rack that need to be check for torque/tightening ? phil

Tire pressure can be critical, factory recommended is fairly high and overall is best for street use I've found. A slightly bent wheel can cause this as well, as can caked mud or debris on the inside of wheel. As has been mentioned earlier, wheels center on the hub rather than by lug bolts, check this. A severly worn tie rod end could cause this, usually alignment will not unless it's been knocked way out due to an accident. Very irregular tire wear scalloping due to severe underinflation might cause this even though tires are correctly balanced. You mention the Hunter balancer, but no mention is made if the balancing was done correctly. I'd check that first! My car has Pirellis at 30% good on front, Sumitomo HTZR ll on the rear angularly worn from 95% to 80% due to negative camber. Running 3 piece aftermarket wheels, RR was severely bent, I removed the tire and straightened in a press and had it rebalanced. Hands free over 100mph and not a hint of shake, rear feels good as well up to 135mph. Hope you get it sorted!

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what do you mean by 'wheels center on hub ? are there many ways to mount the wheel on the car ?

The hub has a raised register that locates in the center of the wheel to assure its concentricity. This is often lacking with spacers and even some aftermarket wheels that are somewhat universal rather than Porsche specific.

It could be a bad tire.

Any chance there is water in the wheel/tire ? Once you get them to spin it and zero out the balance next time ask them to spin it a 2nd time to see if it stays balanced.

my bet is a bent wheel

Run out on the wheel is exceeded (aka bent wheel) Rotors deformed enough, at least causing a shimmy?

When I had my alignment done recently I was told my inner tie rod bushings were badly worn, and that he couldn't do a good alignment without replacing them. I did so, and after that (and of course after the alignment) the occasional shake/shimmy that had been irking me for a some time previously disappeared. My point ? This could be a worn tie rod or link issue.

+1

Could be a wheel bearing but would be generating some noise.

An easy way to check for worn tie rod bushes is to lift the front of the car a few inches off the ground. Then grab each tire at 3 and 9 o'clock and rock in a horizonal twisting motion. Any lash or play will indicate wear that should not be there. Next is to have someone feel around different areas to help pinpoint the source of the lash if it is not obvious.

I'm betting on a bent wheel.

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Exactly. It could also be a wheel bearing, as stated above, but when a wheel bearing is going bad, you can hear it (most of the time). It would seem odd that an alignment would cause a vibration, but I've seen it happen before. Please post back with the before/after specs of the alignment. - Anthony

I went through a similar investigation last year on my 03 Cab. New rear tires, had the wheels looked at and one straightened, all 4 tires balanced - twice. Issue was a bad front wheel bearing. Had that replaced (and new rotors put on the front brakes) and all was well again. Not a great answer $$-wise, but worth a look. Good Luck!

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How many miles were on your car? Was it sitting a lot? Also, did you have any noise - usually you'll hear a humming when the wheel bearing is going bad.

Like other mentioned, could be a bad tire(s). Try swapping another set of wheels from someone and see if the shaking still occurs. worn front shocks is possible also.

a little grain of salt advice from the newbie....had a similar sounding problem with my kids Mazda Protege. Had a sticky caliper on the left front wheel. Pulled a little to the left from start up. No vibration in first few miles until the rotor heated up a bit and started to shimmy. After stopping, the rotor cooled, and the caliper released its grip a bit. rebuilt the caliper. Rotor was fine.

OK, I know this is pretty basic, but has the tire been checked for the "feathering" or "scalloping" condition? You can actually feel some bulges when you run your hand around the circumference of the tire. Tires with this condition cannot be balanced, or not well balanced. The only solution is to replace the tire. ...Rickker

I am back from the shop...Unfortunately the shaking is still there, coming right above 55MPH, at 65MPH it is there clearly, stay same up until 80mph. Did not push it faster than that Mechanic diagnostic and check: - Alignment was done, apparently there was a pretty bad to toe problem (3/4) on one front tire. Consequently that tire is worn on the side, but the mechanics tell me it will wear back evenly, with time. Alignment values: Front: L R caster 7.1 7.3 camber -.5 -.5 toe .1 .1 Back: L R camber 2 2.1 toe .1 .1 - Tires were balanced again today and apparently they were a little off. Note that I had those tire balanced the day before on a Hunter road force machine... So I wonder why they loose the balancing overnight...anyways - Mechanic said he checked for bearing play, flat rim or spot on the tire but could not find anything. I am a bit confused as the shaking is still there. I am afraid I will have to start the debugging by replacing parts I heard in the past that it is possible to balance tires while they are ON the car. Do this really exists ? at least I could confirm my problem in a logical way. I think I will switch the tires first. I have michelin pilot sport sp2 right now, pricey to change just for the test, do you think I can try some cheap sumitomo in the front for the sake of this testing ?

At this point I would be willing to bet that it's a tire. I've had this happen on more than one vehicle in the 3000 or so years that I've been driving. Can you find someone else nearby with a 996 or 993 that you could swap tires with for a test? You could just swap out the fronts, go for a drive, and then swap them back.

I'd put money on a bad tire. Once it's scalloped, it will never be the same.

Try a set of the Sumi IIs on front. They are an excellent tire for your test, if the shaking goes away, order a pair of rears. Also, like anything else, re the Hunter balancing, Snap-On tools do not guarantee quality work. Good Luck

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+1

Are you sure you don't have a spacer on your car? [just had to ask] -td

my bet is you need an new shop - this is a no brainer for the right guy... I cant believe (if you took it in for a shaking wheel) they gave you the car back with the same issue find a new shop

46K miles when this was done, and no sitting. Almost daily driver... Didn't really hear anything, but sure felt it from 50-70 mph. Regarding the latest posts... I agree with looking at another shop. I went to the tire and wheel guys first, but once I got to the specialist - Gerber in Seattle - they had it sorted in no time.

For info my car is a 2003 with only 27,000 miles, so I bet it sit in the garage most of the time. Does sitting in the garage could cause something special - flat tire - bearing problem Anyways this week I am taking the wheel off myself to check them out in very details. Then I'll bring the car to my local official BMW dealer, hopefully they will find what is going on. If not I'll order a set of Sumitomo and get from there. About the spacer, I could not see any when the wheels were off. The tires don't stick out and I have 225 in the front and 295 in the back. They are flushed but not sticking out.

whats with people

I ordered a set of Sumitomo III's for my front, and they should be there next week for testing. In the meantime, I was looking at my rotors and I see they are not worn flat like the rear rotors, but instead when I swipe my finger across them from the center toward the outside, the rotor feels wavy. Is that a normal thing ? Also when I turn the wheel, with the car on jack stand, it is not so easy to turn, but again I have no experience in doing so with other car. To give you an idea or the resistance, when I try my best to make the wheel spin, I can at best get two full turn of the wheel. During the spinning I can hear the brake pad friction with the rotor. Today I had a strange run, I had a hard launch with the car and then up to 70mph, no shaking. I made a U-turn to drive again on the exact same patch of road, and then it was shaking.. this drives me nuts !

perhaps if you built a giant wooden badger................................................ I hate to ask, who is installing the tires the brake thing is normal, as is the fact that the wheel truns when its in the air and the rotor touches the brake pads a tiny amount you realize that you have not listened to the advixe that you asked for.... right.... I mean its frustrating to have your car acting funny, but several people have suggested that you take it to someone that knows Porsche and you opted to look at it yourself, then order new tires, then maybe take it to the BMW dealer.... seriously, you are digging a deeper hole than you need to here IMO

I am gonna install the tire at a local shop, one listed in the tirerack installel list. They are called rick's tire warehouse. At least they have a Hunter GSP 9700 tire balancer. If all fails, next step, I will have to drive 6 hours to Dallas and bring the car to RUF or a Porsche Dealer... Phil

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Dude, lighten up on him. He is listening to advice, just not yours. He's going to try new tires, which several of us have suggested.

the rotor actually looks good - OH so the Porsche dealer is a 6 hour drive, that makes more sense,.... and I am not trying to be a d!ck

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fair enough....

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You don't have to try Ed...it appears to come naturally ? j/k ( no seriously I am joking) That story with having to exert effort while trying to turn the wheel doesn't sound right. It may be that the pads are dragging/hanging on that side....are they very low?? It could be that they are fine sometimes, then after an application of the brakes, maybe during a turn, they stick and that could well be the cause here. Make sure you tell that story when you take the car in...

can you shoot a pic or two of the tire tread... also a wider shot of the wheel - please

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sorry - really I spent last nigh trying to give a guy some pointers on buying a car and today others "helped" and he posted this "Thanks guys. I'll just get my money back. F*** it... I'll buy a house with that money and get a Hyundai next to my VW GTI. With you guys,you can't buy anything... DME...PPI...IMS...RMS...BLABLABLA...you totally changed my buying mood. " kinda put me in a bad mood, I thought he had a brain and wanted to learn... shame on me

@ivangene, I just decided to get with the tires as I lost faith in the local shops. So I'll switch tires, then next step I'll go to RUF in Dallas. I don't think anybody around here can handle this sort of troubleshooting. About the brakepad, I'll try to make a video of the wheel spin and the sounds it makes. the sound is relatively linear so I don't think it would indude steering shaking but again...who knows.. I'm off to take some pics of the tire thread and wheels.

here are the pics and a little video of the wheel spin on jack stand: http://www.youtube.com/watch?v=hkJxjeeaIow

Brake sound is OK. No worries there. As you probably know, vibrating steering wheel is virtually always a balancing issue. I can knock my wheels out of balance on the track quite easily - the tires spin on the rims. Try using some chalk or a white mark of some kind to mark the location of the valve stem on the tire. Then drive around and see if the tire is in the same spot. If your tires are spinning on the rims, you can use some aquanet next time they are mounted. Also, some things you can try before you drive 6 hours: try switching sides l/r on the front. swap the lugs front/back - and if you have locking lug on the front, move them to the back so you have 5 identical lugs in the front. take the wheel off and clean the carrier. Sometimes there is gunk that builds up between the wheel and the mounting spot. Search really hard for a set of wheels you can borrow. I think you might even get away with some VW wheels. Can you take a wheel off the front and take a picture of the carrier? WOW - the PORSCHE lettering on your brakes is so nice and white! Get you some brown in them. -td

argh I wished I had red caliper always wanted some of those, but I'll wait for my next 911 Good idea to mark the tire for spinning. I know that when they balanced the tires they had to make them move on the wheel and they added tons of 'oil/grease' on the rim to make it easier... I never thought the tire could move once on the wheel under pressure. I'll also try to swap left and right tomorrow and at same time, I'll take shots of the carriers. I wanted to check the inside of the wheels anyways. I need to buy some Champagne for the day I find what is going wrong ! Phil.

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The lettering turns brown when the calipers get really, really hot. 2.jpg -td

Agreed - nothing to do with the brakes. I thought you were having trouble turning the wheel by hand, like actually having to horse the thing around using all your strength (duh). Keep us posted of course.

is that a sticker that indicate the heat on the caliper ? pretty cool. I am glad to know my car wasn't tracked too much then Nice little thing to know when you purchase a car... not that there is anything wrong with tracking the car... but good to know.

scratching my head. (thanks for pics and vid) you have new tires coming, if that doesnt do it... the rims are out of round. if tire rack suggested the installer they might know how to check them, ask when/before installing to save having to take the tires off for the straightening sucks that its such a long drive to the shop...is there a local chaper of PCA that might have ideas where to go - try 6speedonline as well??

Should be righted going to Ruf. I think a shop has to have a guy that has raced and experience a 996 and 997 to really know the water cooled. I know some tires end up making more noise when wearing more and I imagine some will tend to do the vibration. What ruf is probably going to do is listen to your story of hisory of problem then disreguard since the others evidently weren't on the ball and take off on their path of diagnosing. Don't feel like they aren't listening to you. Just feel like you aren't running the hot set-up they can supply yet. Could even be suspension as far as I'm concerned and ruf should be an ace at that.

There is NO Rennlister in TX that will offer to lend you some STOCK wheels to test the issue before you buy new tires? I just noticed your rims are not OEM.

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Lubbock is a LONG way from just about anywhere in Texas. Pretty sure those are BBS wheels btw.

the wheels seems to be OEM, I have the car window sticker and it says Turbo look II wheels. About the shop, I am afraid the PCA people told me that when they have problem they have to drive to Dallas to a dealer or RUf. The thing is roads are so bad here, I should be able to live with the shaky steering wheel but my OCD is taking over

LOL @ OCD ! and those are not OEM wheels

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+1 on that. Pretty sure they are not OEM. The Turbo Look II wheels were I believe Turbo Twists. I thought they were BBS, but I can't find a BBS that looks exactly like that. Could also be Champions, although they currently don't make a wheel that looks like that either.

ok so here we go for some pics of the wheels and hub today I switch the wheels left to right, right to left. And also marked my tired to see if they wold move from the rim... THEY DO ! arhh after simply a couple miles I looked and the mark had moved already an inch ! I did not had time to look into it further... but this weekend I'll get some more measurement. Strangest thing also... after switching the tire, the shaking seems...reduced.. I am a bit puzzled. Still some shaking but much less... I think having new tires and make sure they don't slide on the wheels would be an improvement. what do you suggest to avoid the tire slide on the rim ? I already have one suggestion in previous post but I wonder if there are other ideas

Aquanet. $0.99 kind. Seriously. It will stop the tires spinning on the rims. Track "secret." -td

I don't use that much weight on my rims. I gotta tell you there are some roads tht just make the steering wheel shake. Some roads even though looking super smooth have a thing about them that causes the sensation of out of alignment. Could even be only certain lanes of the same hwy. I was having some wobble shake the other day but today the same stretches of road no problem. Must just be certain lanes depending on speeds

Really rough roads can cause bump steer which should not be confused with steering wheel shimmy. Bump steer is the tire reacting to hitting a rough spot, hole, dip, seam or something on the pavement. Shimmy is quick and small movements that increase or decrease as speed changes. Any shop at all should be able to mount your new tires and balance them, it's not a Porsche specific thing. Even an old bubble balancer should work with an operator that knows what he is doing. Good luck

I still think its the wheels not the tires.......clean up the calipers though....please? A good pressure washer will get rid of a bunch of gunk that is in your wheel well. Sorry I got side tracked.

About the Aquanet thing, how do I apply this ? I assume I have to put it between the tire and the rim, right ? So I have to go to the tire shop and ask them to apply it ? I will do some road testing tomorrow and report about the tire sliding issue. #sneak pete: The car will also get a good clean up #pac996: I see the new Porsche Turbo wheels on your 996, are they 'replicas' ? I think the Turbo wheels dont fit the narrow bodies, right ? Phil.

lol @ auqanet - I use that one bicycle grips too... easy on, stay put! so let me get this right.. you marked the tire and the rim and after a couple miles the marks rotated? thats something I would have never thought of. Did you check MFG year of your tires? sounds like a new set of sumis is the ticket !

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about age: I have one tire from 2006 and the other from 2009. they look like they have the same amount of wear though. is this aquanet ? http://www.drugstore.com/products/pr...203&catid=3562 Hairspray ?

yup about a buck.. get pink... extra super hold

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Roger. It's hairspray. Make sure you get unscented Have the tire shop put it on the bead when they mount. Starts off slippery (for easy mounting) and dries like superglue. Tire will not spin on the rim. -td

you can srpay your hands before doing things that require a sticky grip too.... somehow I just know this wont turn out right

I feel for you, I HATE getting any shimmy or vibration in the steering wheel! If you checked all the obvious suspension parts, it has to be : 1 - Tires - they could be out of round from sitting, or, just one could be slightly off. 2 - Rims. One tiny bend on the inside lip can cause all kinds of vibration. 3 - Rotors. If you notice a shimmy when you hit the brakes, well, you get the idea. I had a 944 that was getting a shimmy above 60 mph. Drove me NUTS, until I brought it to a genius. He took the tires off the rims, and found water bouncing around inside them from what must have been a bad gas station compressor! He also re mounted and balanced them, and that cured the problem for me. Good luck!

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You mean like trying to open the pickle jar right?

Not sure if the rims are oem or after market. The Pclub president used to own the car but a later owner put the rims on. They are 235/35/19 and 275/30/19. I used to be in a tire store in Portland and looking at the amount of weights I'd go after the balance again. You might try looking at instruction from the weight manufacturers. I'm not sure it is adviseable to stack weights in two or more rows like its arranged. It also looks like you might be fighting a deformity since weights are going to both sides along with the marks left by prior tape weights chiming in with yah it takes a lot of weights to balance this thing. Once again I some times get what feels like vibrating on smooth looking hwys that have the slight rolling aurface to them. Some tires go that way when they are approaching their lifes end even before the tread gets to the wear bars with out cupping aor much of any other deformitys. Great right

I see some people having this aluminum looking tape onthe weight, is that usefull for regular driving ? Also should I wait for a period of time after the weight have been added ? I mean I am so surprised those weight are just fixed with double side tape on a wheel that is not that clean. They do clean it before applying the weights but still, 10 minutes after application going on highway and shaking those things like NASA astronauts can't be good, no New tires are on the way, I'll keep you posted when they are on. I hope it is not the rims, those things are quite expensive !

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yea, thats the stuff! watch my post on my "sold it" thread,.... you'll see what I opened tonight

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They are the norm and come in different colors if you have a good shop do it. I've got them on a bike that goes just under 200mph. The spot the tape on weights go should be cleaned for best results. They don't normally fall off but somebody might have plans to get knock offs made overseas that would.

I forgot to mention the clip onto the rim weights scar rims.

And the result?....

I wonder if he tried a different stretch of road and the shaking wasn't there. Really amazes me how some of the roads look nice but have weird waves in them from heavy traffic.

What about the Ball Joint/Control Arm? I have a very light Shake of the Steering Wheel, but it goes and comes on the HWY...

I was out of town, I'll be changing tire this week, and will keep you up to date. Today I only had a very short drive with the car, but for some reason, even above 60mph ..no shaking ! go figure... I'll drive ti tomorrow and update you guys. The previous owner of the car, just sent me some history paperwork and I saw he had the exact same problem in the past, described on the dealer invoice as 'steering shake above 60mph' I emailed the owner to ask him what solved the problem and he told me he had to align the car two times, as the first one did not solve it, but after that it was solved. But he also added that if a wheel was out of bound he had a warranty for it... I believe he is honest about it, but still wonder if he knew something was wrong with one wheel.. Today I stopped by my local BMW shop and they refused to take the 911 for alignment saying they don't know how to do it . !! arghh... this is bias

Before you buy the tires check for any water in the tires. It's not uncommon for shops to have moisture in their air lines and add the water when adding air or filling them up for the first time. The water then moves around in the tire causing a problem that misteriously disappears and then reappears. Also if you feel the shimmy/vibration in the steering wheel odds are that your problem lies with a front wheel/tire, if you feel the vibration / shimmy in your butt (seat bottom/floor board) then the problem lies with a rear wheel /tire. If the tire is moving on the rim then that too could very well be your problem. As well as the obvious bent wheel, bad tire, etc. Let us know what ends up fixing this haunting problem.

I have made some marks on the tire to see if they are moving, so far nothing, but I barely driven it. I can clearly feel it in the steering wheel. Tomorrow I'll go on the highway with my camera to show the shaking .. if it occurs! About the water problem is there any way to get rid of it without dismounting the tire ? I mean my tire people around here are so incompetent it is scary. the only thing they want to do is a quick *** job. So far I could not located anyone interested to take the time to do things right. Could it be possible to may be open the valve completely for a few days to dry/air it out ? This is not my daily driver so I could do that. Did you see for yourself water in your tires ? I wonder how much needs to be in there to make a difference ? I assume at least a couple of tea spoons, right ?

I had a similar issue with a Mercedes, I drove it like that for 50k mi and kept taking it back to the dealer... right before I sold it i told them i was just going to come back every day and drop it off until they fixed it.. turned out to be a bad ball joint with just a tiny bit of play in it... must have been defective because it did it since nearly new and went away as soon as they changed it. Just thought I'd throw that out there....

Do you think a worn ball joint play can be tested by pulling it by hand ? to check for play ...

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Usually dismount the tires and remove to get the water out. I have owned 3 independent repair shops over the years, as well as worked as Serv.Manager at the local Porsche dealer for many years, etc , etc. and yes, I have seen it many times from reputable shops and non reputable shops. The symptoms are pretty consistent where the mystery vibration comes and goes at different speeds and times. If it were a bent wheel it should be consistent at the same speed all the time so I doubt thats what it is. Moving tire ? - Thats possible. Bent balljoint, bad bushing, suspension part ? Possible also, although usually more consistently a vibration. Bad tire ? Also possible, especially if the belt in the tire is damaged. Bad shock ? Maybe ? Could be sticking,binding, or even not dampning. The way you say it's in the steering wheel I would check the front tires first. Good luck, and let us know,

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I honestly couldn't tell you.. usually u can test them via that method.. but the dealership couldn't figure it out until they replaced 1 thing at a time until the issue went away. But it does sound similar....

my Tech also told me that older tires or tires that have been tracked can have broken/worn belts that will give a vibration at a certain speed and temp...

I had a similar problem. Mine turned out to be a bent rim.

I wonder if you took a picture of the rim? I mean could you see the bent on the rim when you look at it ? I wonder if you can always see it form the inside of the rim, or if you have remove the tire to see it.

If you had a bent rim it wouldn't come and go.

This was my "seat of the pants" rear vibration that turned into a slow leak. I finally took the tire off to dunk it in water to see if I coud find the leak. I found this; Near the crack it had about 1/2" of run-out. There was no other damage on the rim or tire?? I think the run-out happened when the crack relieved some stress.

Ok after a week of silence and puzzling driving, I have to report that all week the car has been driving without steering shaking! I did not do anything new to the car, and as you recall, after my alignment, the steering was still shaking above 60mph. After reading that tire inflation might play a role, I decided to deflate my tires 1psi at a time and to some test run. Even though the shake was still there above 60 mph, even at super low pressure, once back in the garage I had to re-inflate the tire with my little $20 compressor, and after that... I had to go to Mexico for a wedding... but that is another story Anyways, since I am back, the car drive just fine ! So far, I think some water/moisture might have been in the tire and when I deflated my tire to almost flat it went out, and my little cheapy compressor seems to have done a good job inflating without H2O. Unfortunately, no scientific explanation on this one. I did not see it with my own eyes but I think that was it. I will keep you up to date if it comes back. I am really frustrated that it disappeared just like this, without anything major done. The guy who did my alignment did tell me that I had a serious toe alignment problem and one of my front tire was worn improperly and that the new alignment would help worn down both my tire evenly over time. So that might be another explanation, even though it seems flimsy.

That's good news, did you end up replacing all 4 tires in the process?

Nope everything is the same, same tires, same wheels. Only change was the alignment and then the air.... Puzzles me !

Wow. well at least your rough ride is history.

Hi there Well, the scrapping noise in your video is probably the inner brake disc cover touching the disc. You can poke a screw driver between the spokes and gently push it off the disc again to prove the point. Had this a couple of times after some hot running on circuit. As mentioned by others, your wheels look great but are definitely not OEM and you've got way too many weights in there to think all is well. Aftermarket alloy wheels can be of very variable quality, usually much heavier (hence more balancing weight required) and regularly don't have a good hubcentric fit. Don't be surprised if every time you refit the wheels you have a slightly different mounting point and therefore variable levels of imbalance. Being aftermarket could also explain why the tyres are spinning badly on the rims. The fact you can go through periods of no wobble says the suspension is probably fine so the problem is most likely all in the unsprung weight of the wheels and tyres. If the problem comes back (IMHO it will, sorry) I'd highly recommend checking the wheels have no warping, run straight and that they sit snugly on the hub (no side to side movement whatsoever). Also make sure the bolts are torqued to 130Nm (96lbft I think). The ultimate test would be to fit a set of OEM wheels (18" not 19") with the correct pressures and OEM tyre sizes. BTW 19" rims do create a harsher ride and require lower than OEM pressures to avoid the front bouncing because of the lower profile sidewalls. Interested to know how you get on, been through this kind of stuff a couple of times myself and always frustrating!

Right now the situation seems stable. I'll keep the thread alive if something arise. I feel a very slight shake but I think I am getting picky. again I can feel a very different feel when the road id bad or when the steering start to wobble. #oze172, are there any non oem you think are as good as oem ? FIKSE ? CHAMPION I know it is like another whole thread but my be you have some experience on that. I want to get some oem wheels but their quality seems questionable as I have seen bunch of them cracked and stuff.

Philooo - Check out this link - post #9 https://rennlist.com/forums/996-foru...i-florida.html These are the wheels you have. They aren't OEM - and if you are thinking of going OEM, I think you'd be better off than with what you have from a weight perspective alone. Those "Modular" wheels were popular 2-3 years ago as they were dirt cheap and were one piece wheels that looked like three piece (the bolts along the edge are for show). Wheels looked good, but I think they were pretty heavy..... BTW - if you have the tires balanced on a Hunter machine, it checks for the rim being out of round at the same time - so if the tire place knows anything of what they are doing, the Hunter machine checks for both the tire and wheel being out of round along with balancing.

Hey, I know a fair bit on the subject but don't consider myself to be an out and out expert because I'll never change from my OEM Sport Classic II split rim alloys, see attached, even though they're a pain to keep clean! My experience of "replica" wheels is via a few friends and some have regretted it; citing a change in handling (weight), continual wheel balancing problems (manufacturing inconsistencies) and having to retorque wheel bolts regularly for whatever reason. After market wheels (own brand and design) are typically more expensive and employ better manufacturing methods. BBS, OZ etc. You get what you pay for. I personally put a lot of faith (and money!) in tyres, brakes and geometry to consistently get the most from my car at all speeds as safely as possible. The quickest way to undermine all of that is to put on some wheels that aren't capable of performing as expected. Just to be clear, yours "could" be ok, but they're a question mark without the evidence to back it up for peace of mind. If you do find the wheels need changing I'd recommend going back to 18" OEM of your choice for a better driving experience. Excert from Tirerack on manufacturing techniques: http://www.tirerack.com/wheels/tech/....jsp?techid=90 One-Piece Cast Wheels This is the most common type of aluminum wheel. The casting of wheels is the process of getting molten aluminum inside a mold to form a wheel. There are different ways this can be accomplished and although it sounds simple, this is truly an art when done properly. GRAVITY CASTING Gravity casting is the most basic process of pouring molten aluminum into a mold utilizing the earth's gravity to fill the mold. Gravity casting offers a very reasonable production cost and is a good method for casting designs that are more visually oriented or when reducing weight is not a primary concern. Since the process relies on gravity to fill the mold, the aluminum is not as densely packed in the mold as some other casting processes. Often gravity cast wheels will have a higher weight to achieve the required strength. LOW PRESSURE CASTING Low pressure casting uses positive pressure to move the molten aluminum into the mold quicker and achieve a finished product that has improved mechanical properties (more dense) over a gravity cast wheel. Low-pressure casting has a slightly higher production cost over gravity casting. Low pressure is the most common process approved for aluminum wheels sold to the O.E.M. market. Low-pressure cast wheels offer a good value for the aftermarket as well. Some companies offer wheels that are produced under a higher pressure in special casting equipment to create a wheel that is lighter and stronger than a wheel produced in low pressure. Once again in the quest for lighter weight, there is a higher cost associated with the process. Spun-Rim, Flow-Forming or Rim Rolling Technology This specialized process begins with a low pressure type of casting and uses a special machine that spins the initial casting, heats the outer portion of the casting and then uses steel rollers pressed against the rim area to pull the rim to its final width and shape. The combination of the heat, pressure and spinning create a rim area with the strength similar to a forged wheel without the high cost of the forging. Some of the special wheels produced for the O.E.M. high performance or limited production vehicles utilize this type of technology resulting in a light and strong wheel at a reasonable cost. BBS has used this technology for several years in their production of racing wheels for Formula One and Indy cars. BBS's RC wheel for the aftermarket is an example of a wheel produced using spun rim technology. CNC Mill In forged wheels, computer numerically controlled (CNC) mills add the cosmetics and the bolt circle to exacting tolerances. Forged The ultimate in one-piece wheels. Forging is the process of forcing a solid billet of aluminum between the forging dies under an extreme amount of pressure. This creates a finished product that is very dense, very strong and therefore can be very light. The costs of tooling, development, equipment, etc., make this type of wheel very exclusive and usually demand a high price in the aftermarket. Multi-Piece Wheels This type of wheel utilizes two or three components assembled together to produce a finished wheel. Multi-piece wheels can use many different methods of manufacturing. Centers can be cast in various methods or forged. The rim sections for 3-piece wheels are normally spun from disks of aluminum. Generally, spun rim sections offer the ability to custom-tailor wheels for special applications that would not be available otherwise. The rim sections are bolted to the center and normally a sealant is applied in or on the assembly area to seal the wheel. This type of 3-piece construction was originally developed for racing in the early 1970s and has been used on cars ever since. The 3-piece wheels are most popular in the 17" and larger diameters. There are now many options for 2-piece wheels in the market. The 2-piece wheel design does not offer as wide a range of application that a 3-piece wheel allows, however they are more common in the market and the prices start well below the average 3-piece wheel. Some 2-piece wheels have the center bolted into a cast or cast/spun rim section and other manufacturers press centers into spun rim sections and weld the unit together. When BBS developed a new 2-piece wheel to replace the previous 3-piece street wheel, they used the special rim-rolling technology (originally developed for racing wheels) to give the rim section the weight and strength advantages similar to a forged rim. On the high-end of the 2-piece wheel market you can find wheels using forged rims and forged centers. Since these are only sold in small volume and due to the high development and production costs associated with the forging process, they tend to be on the high end of the price scale. Good luck, I hope it all works out!

I wrote a post earlier but got distracted and lost it! Take a look at this article on different manufacturing methods http://www.tirerack.com/wheels/tech/....jsp?techid=90 There are 2 sorts of non OEM wheels; Replica and aftermarket. Replicas typically adopt low cost manufacture methods that mean they weigh more and can be fairly unbalanced compared to original. Despite being heavier they're also weaker. Aftermarket have their own brand and designs. BBS and OZ fit into this category. Might look the same but way stronger and better balanced because of the multistage manufacturing process. Basically you get what you pay for. My personal favourite wheels are BBS on a Porsche, but I am biased! Get the rims checked out for warp and hub fit. I'm more than happy to be wrong but it's worth it to get the driving fun back on track Hope it all works out!

Hi Tried to reply a couple of times but the posts are getting blocked for some reason?! There are loads of good aftermarket wheels. Basically stick to wheels from companies with own designs and brand, BBS and OZ for example, that use advanced manufacturing methods such as rim spun or even forged. Replica wheels are quite different and much more liable to cause problems on high performance cars because whilst they look the same they are physically quite different and therefore will behave differently. Just to clear, Replicas can look the part but don't assume they will perform like OEM at the edge of the envelope. Do a search on alloy wheel manufacture, loads of good sites about that explain the different manufacturing methods. J

Ok so here is an update, I changed the rims and tires. I bought a set of used OEM 5 spoke rims. I checked the rims and they were round and true before mounting the brand new tires. Same vague steering problem at speed with shaking. So, .. - Can I check myself for things like torque on the steering system ? - I see some aftermarket part selling bushing or stuff like that, suggesting me that the OEM part might be of inferior quality ? can they be checked ? If anyone had a list of things to play check, I'll be happy to spend more hours on this as it really drive me nuts. Also is there something to get stiffer/sharper steering ? mine feels too much like a GT. My wife Mini cooper got sharper steering ! May be my whole suspension needs to go to PSS10...$$$

Take it to a porsche dealer for a fix. I've heard some say they don't trust their local or other dealers and hope at least you have a dealer around your area that does the right thing. I think you have a suspension or rotar problem. Not being there I could even imagine the underside plastic cover could be catching air buffeting making you think its steering problems. What ever the case a good dealer should know whats right and at least be able to spot if its non standard or else wise on your car to have the symptoms you don't like. Good luck man.

Sorry to hear it's still the same. Did the guy who did your alignment check your ride heights and nose down attitude? The rear suspension can collapse over time leaving the front sticking up in the air. If the car is nose up it will literally start lifting the front off the ground making the steering go light which will give you these sort of vague and bouncy symptoms. Any hint of headwind or sidewind and it'll be worse. A quick and dirty way to get a basic idea of the cars attitude is to get a digital spirit level and put it up against the longitudinal chassis runners under the car...see attached. Negative towards the front is a good starting point!

Lower via H&R springs from Tire Rack will change the response nicely -

oze172, very good point, as I feel the steering is too light when I get wide open throttle. Also I always thought the back was sagging a bit. I am gonna get a reading on a digital level and report. Can a couple of you guys tell what are your digital level read ? that would help to check it against.

If you already suspect the rears dropped it's probably best to go straight to ride heights. They will have settled so the important point is whether the difference front to rear has been maintained. My ride heights were 140mm ( dropped 8mm) front and 135mm ( dropped 28mm!) rear which was a brch to drive and much the same as you're experiencing. After fitting KWv3 struts my heights are now 106mm front and 123mm rear and the car behaves beautifully Credit for the pictures to Loren @ Renntech.

Ok so now to add to the confusion... How do i know which suspension I have ? usa standard, row standard, row sport ? When I purchased the car nothing was mention about suspension upgrades so I assume I have the base usa standard, but if that is so... my measurement are way too low, by the way I have 18" inch rims. Looking at my pics you will see that I measured rear +- 145mm front +- 145mm This doesn't really fit anything standard but at least it seems to show a big sagging in the back as all specs show the rear should be higher than the front. But in my case both measurement are the same so the car is pretty much flat. The two last pics show indeed the car is flat on the ground. Garage floor is -0.8 and car is also -0.8 (level arrow on the other side as the level is upside down). How to correct this then ? is it the springs ? or the shocks have to go ? I wanted to go pss10, but it is pricey and wifey is gonna have a fit

OK............how about measuring the other way. What is the measure from the garage floor to the underside of the front fender taken at the center of the wheel arch? With the X74 I have 25". Prior to the X74 I had 26 3/4" or 40mm taller with 18" wheels and STD US suspension. You can figure the numbers from there.........

After all the pain looking everywhere for the reason behind my steering wheel shake, I finally found the solution! Even though my car was aligned last month while I was trying to solve my steering wheel shake. I figured I should probably try another alignment... just in case the first guy did not know what he was doing. So I went looking for a new shop with the proper equipment. I found a shop with a good Hunter alignment machine and decided to give a try. This time I stayed at the shop looking at every single move of the mechanic, just to make sure it all made sense and readings were correct. I did not want to go do a third alignment ! ..and.. bingo ! no more steering shake !!!!!!!!! Man, after all, it was just a job poorly done since the beginning ! Anyways see attached the values, before and after. you can see some values seriously wrong in there so I assume they are the culprit of my steering shake.

You're front toe was horribly out and the rear right was well out too....! New numbers look a lot healthier. Glad you've got it sorted and without anything major in the end

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Plus 8 pages of posts..... Good to hear you found the culprit!

Finally a solution to your shake. Bet you enjoy your Porsche now that you corrected your alignment.

Great zoom factor now. Glad you are a happy cruiser now. Enjoy

Don't know if this little tip will help, got this from an old Porsche mechanic "make sure the locking wheel lug is in opposite of the tire valve stem " Gerry

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That applies only to the old style, key type, locking wheel NUT, when the socket style nuts arrived with the 17" wheel, that type of locking nut weighed the same as the normal wheel nut, so positioning was not important. The 986, 996, etc, use bolts and the locking bolt can be positioned anywhere, although it looks better to be opposite a valve.

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Glad it appears to be sorted but you are still going to want to upgrade your stock suspension. The US stock stuff in particular is mushy and the ride height is embarrasing. You don't need PSS10. The PSS9 stuff is plenty good. Parts new will cost about $2K, parts used will be $1K, assuming you can find some. Installation is a breeze, you can do it yourself. Yes, you'll need another alignment but that's the cost of happiness. I've been doing this for some time Philoo and you have reached the point that all of us reach eventually....yes it's time to stop telling the wife what you are doing and how much it is costing. Trust me, you and yor wife will be happier for it. I rationalize it this way: I love my wife, and I know that it upsets here when I tell her how much money I spend on my car. So why on *earth* would I intentionally upset the woman I love? Am I some kind of monster? No I'm not. She doesn't want to know these things. I sleep well at night.

During my PSS upgrade I was thinking about camber plates and other fancy alignment stuff, but after this alignment problem, I am not sure my local shop can handle complex alignments. Are camber plates really useful unless you are an experienced driver ? I am fast but nothing like a track rat

Set your front toe to 0 and forget about it, you now have zero camber on the front, good for tire wear. You really don't need much camber unless you are tracking it. I like as little caster as I can get for around town. Looks like you got a 'nice' street alignment the last time. I bought my own alignment tools since it is so hard to find shops/people that can figure this simple stuff out.

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Funny you mention that, as I was about to do the same ! can you list what equipment you have ? I was under the impression that you need : - 4 turning plate, BTW my shop had real nice turning plate in the front but simple circular piece of wood under the rear tire and it seems to do the trick. - a system with perpendicular bars and string - some 'stuff' you place on the rim, which usually come with a digital level right ? Any good DYI home alignment ?

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Agreed! My wife had no idea I spent $2,800 for tires for my 996 in 3 years of ownership. What she doesn't know won't hurt me! BTW, I already have amassed $17.23 in my "secret fund" to get another Porsche! Another 55 years and I'm good to go!

I bought a Smart Racing Smart Camber tool along with a set of Longacre toe plates, works for me. Over on Pelican there is a good thread on DIY alignments

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did you compare your home made adjustment with a professional machine ? I wonder how accurate you can get with those tools. I have to say that the smart camber tool and the longacre plate seems pretty easy to use... interesting

I go by drive-ability (you know this part after your travails) and tire wear. Accurate is a relative term in alignments. It is not rocket science at all. Pretty easy stuff, toe has the biggest drive-ability factor, camber is just the tire lean, and caster you usually never need to touch unless you have a pull or low speed sluggishness or high speed wandering. Once you play around with the settings you will see. Try it, you 'll like it. BTW, I go by inches for toe and degrees for castor/camber. Those new style print outs like you have are just BS to confuse people. One careful person with simple tools can easily do a better job than an idiot with all the high tech stuff.

did you ever feel the need for turning plates ? what are you putting under you wheels so that you can adjust them to the new setting. Looks to me like turning plate are the most expensive item

I don't have turning plates. Lots of people use 2 pieces of linoleum tile with grease in between and I think Harbor Freight sells cheaper plates if you think you need them. take a look at this thread on Pelican lots of good DIY info http://forums.pelicanparts.com/porsc...upgrade-9.html