All,
I have just had new rotors fitted to the front of my 964C2.

I now seem to have a slight wobble through the steering between 60-70mph which was not there before. I am going to get the fr wheels balanced up just to make sure but I am certain that this problem has appeared since the rotors were fitted.

Does anyone have any ideas/experience of this sort of problem?
Thanks,
Kevin.

 

I would have thought the wobble would exist all the time if it was the rotors and would be noticable at anything other than low speeds. Does it disappear at 70 or just begin between 60 and 70?

 

The obvious question, surely no dirt between the hubs and discs or between hubs/wheels front??

 

Re torque lug nuts, sounds simple but uneven pressures can cause similar problem.

 

Your rotors won't cause wobble unless your foot is on the brake pedal. It is most likely tires out of balance (maybe the weights got knocked off in the process of doing the brake work).

 

If you jack up the thing and spin a wheel , does if spin true or does it have run out ?
Could be side to side or up down . Could be a tire going bad , delaminating . Any funny feeling tread ?

Rotors get ballanced at the factory , they sometimes press in a ballance weight , the ballance of the rotor could be out .

 

This is a longshot....I always align the wheel to the RED lug as is described in the manual,ie, on D90's the valve stem is closest to the red lug, and on the other styles, the stem is opposite the lug. I understand that it is to account for the wheel lock, which is supposed to go on the red stud.

Since it is so simple to put the wheel on the proper stud, I do not have any experience with riding around with a different set-up.

 

Amen to getting the wheel on in the same position that the factory used. I refresh the red paint on the stud as needed just to make sure the reference mark is preserved. Proper torque and preserving the wheel balance weights is also important. All these items are the responsibility of the mechanic that performed the brake work. Does he/she have an explanation?

 

I WISH that were true - I have the same wheel wobble condition with onset between 45 & 70 mph - feet nowhere near brake pedal. Unfortunately, it is intermittent. Mostly happens on cool damp days. Can be severe (rattle your teeth & make your hands numb from violent vibrations on steering wheel).

Apparent cause is a caliper that doesn't always fully retract (right front) & diagnosed by substantially higher wheel/caliper/rotor temp after a drive during which the wobble has occured.

 

Any way of determining the original red stud after the paint has worn off?

 

So it is in agreement that changing rotors will not fix his problem - which was my clearly made point!

 

"Any way of determining the original red stud after the paint has worn off?"
Don't worry bout it . It does not matter unless you have your wheels balanced on the car .
After you change the rotor a few times , any chance that the factory balance is still around .....


"So it is in agreement "
I'd not rule out the rotors just yet .

 

Guys,
Thanks for all the responses, sorry i have been off-line, been chasing around after my 5 and 3 yr old boys!

Got the wheels balanced yesterday, one wheel was 5grammes out , the other 15grammes. Now seems a lot better.

Just to put my mind at rest i am going to put a dial gauge on the rotors to check for run out, does anyone know what the specs are for this, axial and radial?

Thanks as always,
Kevin.

 

PS-Wheels are fitted with Locking nut on red stud opposite the tyre valve!

 

http://www.hunter.com/pub/product/ba...0T-1/index.htm
http://www.stormbalans.ru/eng/prod_ls1F.htm

If the wheel is balanced on the car , all the parts have to be kept in the original position .
If they are not in position , they are no longer balanced .
Once the tire has been rebalanced off of the car or the rotors replaced , the red dot is nothing .