jenskleis

Hello friends,

First of all, allow me to introduce myself.

After three happy years with a 1993 964 C4, I recently up-graded to a 1995 993 C4. (pics will follow!)

It is a great car, and I do think it is a big step forward from its predecessor... even though I loved my 964 to bits.

However, one thing does worry me about my 993, hence my first 993-post.

During a recent trip through Germany, it was time to see how fast my 993 could go.

Much to my frustration, as soon as I reached 190-200 km/h, the steering began to shake. I would lift off the accelerator, which enduced an increase in the shaking until the speed was below 180.

I tried on different types of tarmec, and the problem always occurred between 190 and 200 km/h.

I have had the wheels re-balanced but the problem persists.

My mechanic has checked the suspension and says everything is in perfect condition.

But the car still shakes.

What could be the problem???

My only last thing to check is the 18mm spacers I recently put on the front.

Could the spacers themselves be out of balance?

Did I mount them wrongly?

Is there a special way to fit them, just like one has to make sure the anti-theft nut is opposite the air valve when mounting the rims?

Any suggestions would be most welcome, and I will let you know how I get on.

Take care,

Jens

FLYT993

My car shakes a little too....my control arm bushings are cracked.

JM993

Yorr spacers could be (and likely are) the culprit.

allill

have you tried running the car without the spacers to see if the problem is constant?

Martin S.

I'd be sailing those spacers like Frisbees across the parking lot....front control arm bushings can evoke shake, generally on deceleration. Here is what I'd do:
1. Take out spacers and redo speed run. If no shake, problem solved.
2. Still shakes, put the car on the rack. The mechanic can put pressure on the control arms to see if they need replacing...if they are good,
3. Time to balance the wheels.

IT is Friday..off to the tavern!!!!

Wilder

I bet it's the spacers. I have experience with them on 993s and it's not a good idea to go beyond 12mm in the front, especially if they're hubcentric, or they'll cause shaking and/or instability. Pretty easy to diagnose.

kb

Could one of your front rims/wheels be slightly out of round? Shaking could be pronounced at higher speeds. Of course the spacers are suspect too.

24FPS

in a straight line the 993 should be smooth & tight & actually frightfully stable then a bit disappointing as the limiter kicks in........... (which i don't think you have in europa) woo hoo

hope you don't have 19's w/ spacers & no brace!

jenskleis

Hi guys,

Thanks for the ideas. I guess consensus points to the spacers.

I will take them off and go for an early morning speed test tomorrow (before the Swiss cops hit the highways :-))

FYI, I run the car on stock Porsche 16" rims.

I will keep you posted.

Take care,

Jens

Monique

Another likely cause is a front tire out of round... especially if they are Pirelli junk. Ask me how I know

I had such a problem on my front end: delaminated belt was the diagnostic.

As mentioned by a previous post, sail your spacers; they are often a cause of headaches as they move the stress point outboard and accentuate any problem.

Marlon

According to ASG here in Virginia, my 106K mile 95 993 has worn out lower control arms and the tie rods are suspect. My car has the same symptoms and the rack brace did not help it.

jenskleis

Hi guys,

Yesterday I took off the spacers and this morning I took the car for a test run.

The shaking is gone!!!

Thanks a lot for the advise.

Take care,

Jens

Monty

Have you drilled out the dust from the the front disc vents recently? Some rotors I understand have balance metal in there and you can drill these out accidently when cleaning the dust.

24FPS

how do you like? how does it compare to the 964? esp. in the twisties?

hope it scares you... in a good way.

jenskleis

Hi guys,

My first impressions of the change from a 964 to a 993 is that the 993 is more refined in the way it handles.

My 964 C4 was equipped with a combination of Eibach and Bilstein suspension, 17" OEM Cup rims plus a strut brace, which made it handle very vell when driving on twisty mountainroads. It felt like a go-cart, albeit a bit jumpy when going over un-even roads.

My 993 C4 had the M030 option from the factory, and runs (for now) on stock 16" rims. It feels softer than the 964, which is surely because of the higher profile tires. However, the rear feels more agile and the suspension is far less noisy than on the 964.

As I like my car to be firm, without being too uncomfortable, I plan to fit it with 17" Cup rims. So, if anyone has a set to sell, shoot me a PM.

Another observation is that the 964 seems to pull stronger from low revs, whereas the 993 gets going at higher revs. But, once the 993 gets going.. it goes like stink!

Overall, I find the 993 the perfect mix of classic 911 driving pleasure (handling, noise, feel) and modern age capability (air con, ride comfort, power steering, turning radius).

Now, being a spoiled person I do miss my 964. If only I could have had both ;-)

Take care,

Jens