marinesniper0318

Hello,

So I changed the tires to new Pilot Sport 2's, rebalanced...still feel a vibration in the steering wheel.

I changed the RIM's and rebalanced, same things still feel vibration.

I had a Porsche certified 928 mechanic look over the whole thing and he did not see a reason for this.

It is very frustrating, prior to the work above I lowered the car using the stock suspension but I never re-aligned it because everyone told me that would not effect the vibration...

It does not vibrate under braking except between 60-75mph so the rotars are probably file, I just did a break job on it.

The only thing I have not changed is the wheel bearings...

Any advice for a frustrated novice...?

thank you ..

Sniper

SeanR

First thought was the wheel bearings. Jack it up, grab the wheel at 12 and 6 and feel for any play.

When they are balancing the tires, are they road force balancing them?

SQLGuy

What did you break during the "break job"? ;-)

More seriously, are these new front rotors, or did you resurface them? One thing my mechanic mentioned that he'd seen was that these rotors will sometimes lose a balancing slug, and they're big enough that they can then unbalance the whole wheel/rotor system. The old style wheel balancing on-the-car setup can correct this, but not a lot of places have that equipment anymore.

Also, are you sure it's the fronts? Maybe the rears are out of balance.

Mongo

I would just change them. They are cheap and easy to replace if you have done a brake job before on this car. The braking system is fairly easy to rip into at the wheels.

Bill Ball

In the 12-6 test Sean mentioned, if there is play, have someone apply the brakes. If the play is eliminated, you have worn/loose wheel bearings. I've seen this several times. If the play is still there, then balljoints, tie rods and the rack need to be checked for play. Your certified mechanic should have done all of this. Less likely but also needing examination are the upper and lower control arm bushings. Also, the wheels and tires may be balanced, but are they true?

Stromius

Go back to your tire store and watch the tire on the balancer. I had a bad set that had visible lateral runout. I saw the lateral of at least 1/2". New tires had no runout and the vibration at 65 ish was completely gone.

Discount/America's Tire was very good about a new set no questions asked. They would return them to the manufacturer under warranty.

marinesniper0318

So yes I changed the rotors and yes they road balanced them. Sorry I should have been more clear the vibration was there even before the break job and the tire change...guess I will swap out the bearings and see if that helps...

svpmx83

Have your alignment checked - old school checks were 30 & 60 mph vibrations were balance related 55-65 mph vibrations were alignment

Speedtoys

Who would say such a thing?

Lower the car..raise the car...you must realign it.

Its fundamental.

S4ordie

I just resolved this issue with my car. I had a bent wheel that manifest a vibration from 60-80 mph. Had the wheel retrued problem solved.

dcrasta

in addition to the 12-6 method (useful for checking for loose or worn bearings) the 3 and 9 method (Grab the wheel at 3-9 oclock (with the car jacked up) and try to move it.. (Best if only one wheel is off the ground). You may have a loose inner or outer tie-rod . This is something most alignment shops can check.

Any steering rack leaks ?

marinesniper0318

Cool thank you all for the advice, I had the vibration before I lowered the car...so would it not be better to align it while the car is lowered the way i like it...?

Regarding the the wheels, I had the vibration with the originals and I now have new ones and the vibration is still there..

I will also check the Tie Rods...

thank you all, this gives be something further to try...!

Sniper