Steering wheel wobble/vibration

vibration
cadillac
cts

#1

Ok so we all know it’s usually warped rotors or possibly a caliber problem. But let’s say u have new of both. And still I’m getting a wobble, not only when I brake at higher speeds, but when I’m on certain roads. Only certain roads. Say about 20% of other roads while driving I get a slight wobble. Not too bad, but a very annoying wobble. I bought this CTS at 35k and now has 45k on it. And again I bought this car for my long commute and a smooth drive. Which I’m not getting. I can’t take it anymore! I’ve got to figure this out. Any advice on what this might be? Getting a wobble in the steering while on super smooth roads. And I know it’s the car because I have a Chevy Cavalier and a Dodge truck in the family that don’t wobble on the same roads. Any tips sure would help


#2

If I recall correctly, Cadillac CTS’s have a problem being sensitive to wheel end vibration frequencies. It just might be that normal brake rotor tolerances are not adequate for this vehicle - and that you might not be able to fix it unless you got lucky.


#3

Rotated tires recently?


#4

Do you get this wobble when you are not braking?


#5

Yes tires have been rotated by Discounts “Best” guy they said. Also, yes on certain roads it vibrates or wobbles too with no braking. Yet our other older, crappier cars don’t on those same roads


#6

CapriRacer, what are wheel end vibration frequencies?


#7

Do you have alloy wheels or steel wheels?


#8

I think they’re alloy wheels


#9

The wheels are fancy after market wheels. I can’t remember the name right now though


#10

Does this wobble sensation only occur during braking? Or even just driving down the road without any brakes applied at all?


#11

I’d have the wheels checked for runout. There is also the possibility that when the rotors were changed, a small piece of debris got between the hub and the rotor or the rotor had some corrosion coating on it that was not cleaned off and was not applied evenly so that the rotor and the tire no longer run true.


#12

Thank you Keith I sure will check those.
George, yes it does wobble just driving down the road in certain roads. Except when driving at higher speeds. 65 and above


#13

TheKennyP asked: "CapriRacer, what are wheel end vibration frequencies? "

Those are the frequencies where rotating components at the wheel end (tires, wheels, rotors etc.) vibrate. This is usually in the 50 to 70 mph range, although an actual vibration may be caused by something else that is of the same frequency when the vehicle is in a different speed range.

He also said: “The wheels are fancy after market wheels. I can’t remember the name right now though.”

That may be your problem right there. Aftermarket wheels generally aren’t hub piloted, like OE wheels are. That may be causing an additional vibration that only becomes perceivable under certain conditions.


#14

Check the wheel for runout or a bent wheel as previously suggested.

Have the wheel and tire road-force checked. It is a fancy machine to measure the contact force of the tire. A perfect looking tire can be way out of force spec causing a wobble.

Also have the service place check that the wheel pilots on the hub, if it doesn’t have them try to get spacers that can be installed to fit the wheel pilot and the car’s pilot. If you can’t get spacers, try unbolting the wheel and index it a couple of wheel studs. Make not of where you started and where you end. The idea is if the wheel is a little bit off-center and the hub is too, mounting them in so the off-a-little-bit centers are opposite so they cancel.

Wheel-end-vibration frequencies relate to the diameter of the tire and the natural frequency of the unsprung (wheel+brake+knuckle+1/2 control arms – the stiffness is the tire itself) mass. This varies by car but is usually 10 to 15 Hz. If the tire is a size to have 850 revolutions per mile, going 60 miles/hr, that gives a frequency of 14.2 Hz. If the natural frequency is 14.2 Hz as well, the car will be VERY sensitive to balance at 60 mph.


#15

I missed the “after market” part of your statement so I have to agree with Capri Racer on the hub size. To fix that, you need hub centric rings. Here is what you are looking for.

http://www.motorsport-tech.com/hub_rings.html

There are other issues with after market wheels as well. Yours may not have the correct offset for your vehicle. Off set refers to the plane of the wheels hub mating surface to the center of the wheel. This is looking at the wheel from the front. Say the wheel is 8" wide. You want the center of the wheel centered between the wheel bearings. The hub mating surface is outside the outer wheel bearing. If the wheel bearing assembly is 2" wide and the hub mating surface in a 1/2" outside of that, the the hub mating surface is 1.5" from the center of the wheel bearing so the off set of the wheel should be 1.5"

If your after market wheels have a 0 off set, the the wheel would be centered outside the center of the wheel bearings and any bump in the road or ever so slight imbalance of the wheel would have a big mechanical advantage on the wheel bearings, easily causing wobble and other vibrations.

If these after market wheels are oversized wheels, like 22" or even up to 30" with tires that look like a rubber band around the wheel, it gets even worse.


#16

I missed the “after market” part of your statement so I have to agree with Capri Racer on the hub size. To fix that, you need hub centric rings. Here is what you are looking for.

http://www.motorsport-tech.com/hub_rings.html

There are other issues with after market wheels as well. Yours may not have the correct offset for your vehicle. Off set refers to the plane of the wheels hub mating surface to the center of the wheel. This is looking at the wheel from the front. Say the wheel is 8" wide. You want the center of the wheel centered between the wheel bearings. The hub mating surface is outside the outer wheel bearing. If the wheel bearing assembly is 2" wide and the hub mating surface in a 1/2" outside of that, the the hub mating surface is 1.5" from the center of the wheel bearing so the off set of the wheel should be 1.5"

If your after market wheels have a 0 off set, the the wheel would be centered outside the center of the wheel bearings and any bump in the road or ever so slight imbalance of the wheel would have a big mechanical advantage on the wheel bearings, easily causing wobble and other vibrations.

If these after market wheels are oversized wheels, like 22" or even up to 30" with tires that look like a rubber band around the wheel, it gets even worse.


#17

I’ve got more information on this site than anywhere else ever! I can’t thank you all enough! I will take this info and see what I can do. I will come back and give y’all an update ASAP. So again, thank y’all very much!!