I have an 02 Legacy Wagon with 95k mi and for about the past 10k miles, when braking at highway speeds, there is a substantial shimmy/vibration felt and seen in the steering wheel. This not felt on the brake pedal, just in the steering wheel, and the steering wheel does not seem to be pulling to either direction. Any suggestions on where to start looking where the problem might be?

 

On a sidebar question, does anyone know if there is an outfit which I can purchase OEM Subaru parts and use my Subaru bucks?

if its happening while braking then i would say you have a warped rotor or 2 up front.

look at your rims. On one of my cars i have a bent rim that causes the car to shake only when braking.

 

Its balanced so it doesn't shake while driving much but when braking it does.. Causing the wheel to shake but not the petal.

 

 

-Justin

+1 on the rotors, I have the same issue with a MY02 Outback. This will be the 2nd set if rotors and I'm going to put these on myself when the weather breaks (get cooler).

 

Front rotors vibrate the steering wheel, rear rotors you feel in the seat of your pants.

 

There are two reasons they do this: one is warpage, the second is a build up of brake materials from the pads on the rotor surface.

 

You can try having them trued by a shop if they have enough thickness, but if it warped, I would just replace them.

+3 on warped rotors.

 

look at your rims. On one of my cars i have a bent rim that causes the car to shake only when braking.

A bent wheel would not make the car shake when braking. You have warped rotors as well.

Classic warped front EJ rotors. Probably gets worse with heat or hard braking, coming off a ramp on the highway, etc?

 

Have the rotors turned, the shop across the street does it for me for $15 each. It's worth a call to see if anywhere does it.

Warped Rotors.

Could also be pad deposition onto the rotors, caused by getting the brakes good and hot then stopping with the brake on for a bit.

 

This feels much like a warped rotor but the cadence is usually once/rotation as opposed to many times/rotation.

 

If the steering wheel vibrates, that's what I'd call warping, if it feels like it gets pulled left-and-right that's the slower cadence I mean.

 

Dave

+4. I'm having a minor issue with that now. It's not uncommon for this to show up at high speeds also and be mistaken for tire balance or belt issues.

Sorry to dredge up a dead thread, but I'm having some front-end problems too. I thought it was the brakes, for sure - I had put new rotors and pads on a year or two ago, but the calipers were getting very, very rusty (rough surface on caliper slides, not enough material to resurface without a machine shop).

 

I put rotors, pads, and calipers on the front this weekend. Guess what? Still vibrates! The only thing I didn't replace was the caliper bracket - can this realistically get warped or out of shape? On the passenger side, the fit between the pad is really tight on one side between the pad and the bracket insert clip thingy. It was like this before, with old clips and pads, and remains the same with new clips and new pads.

 

I know my back brakes are a wreck too, but I don't see how they could really contribute to steering wheel shimmy in addition to brake pedal feel.

 

A ball joint or even a wheel bearing also be a culprit? The car has 160k on it.

Edited August 27, 201015 yr by wondercow2

Think about the conditions under which the problem is most likely to show up, then take a look at these:

http://www.furi-dorifto.com/tech/Subaru_dox/ChaseEWAug06.pdf

http://www.aa1car.com/library/vibrations.htm

http://www.aa1car.com/library/tires2.htm

Think about the conditions under which the problem is most likely to show up, then take a look at these:

http://www.furi-dorifto.com/tech/Subaru_dox/ChaseEWAug06.pdf

http://www.aa1car.com/library/vibrations.htm

http://www.aa1car.com/library/tires2.htm

 

Belated update:

Replaced inner and out tie rods on both sides AND the ball joints for good measure. STILL a vibration when braking, but it's not as bad as before.

 

The good news is I have a new theory- upper strut mount. When the ball joint was out of the passenger side knuckle, there was a LOT of play in the entire strut/knuckle assembly. I didn't notice a similar play on the drivers' side, but I had such a bear of time getting out one ball joint that I wasn't really paying attention.

 

The strut should be more or less rigid whether it's connected to the control arm or not, correct? I am under the impression that the strut mount allows the strut and knuckle to rotate, not move side to side and in and out.

Could also be pad deposition onto the rotors, caused by getting the brakes good and hot then stopping with the brake on for a bit.

 

This feels much like a warped rotor but the cadence is usually once/rotation as opposed to many times/rotation.

 

 

 

Dave

 

 

I had this issue with semi-metallic pads.. I changed over to ceramics and I've driven about 2K on the pads so far and it has not came back.

 

 

like you said it makes it feel just like a warped rotor but it's not just the pad stuff sticking to the rotor.

The strut should be more or less rigid whether it's connected to the control arm or not, correct? I am under the impression that the strut mount allows the strut and knuckle to rotate, not move side to side and in and out.

They can usually move around a fair amount with some effort. The mount has a rubber bushing to dampen/isolate vibration in the strut/knuckle assembly and prevent it from being transfered to the chassis of the car.

 

Check the rear bushings on the front control arms. They are fluid/grease filled rubber and when they go bad will allow the control arm to move around. If there is any dry rot on the rubber or any grey colored grease around them they are bad.

 

If those check out address the rear brakes, and then move on to other possibilities.

Wondercow, What did it end up being??? I am having a similar problem. I changed my front pads and rotors and assumed that would do it but I still get the shaking(only during braking and much worse at certain speeds)......does anyone think this could be related to a drive axel or the front diff???

Let's see, I have an older Subaru brake troubleshooting chart, let me find it.

 

On a sidebar question, does anyone know if there is an outfit which I can purchase OEM Subaru parts and use my Subaru bucks?

 

Yes, subarupartsforyou.com accepts them. I just burned $400 Subaru bucks with them. If you mail your Subaru bucks to anyone, I highly suggest making copies beforehand, and sending it with signature required. Mailing the bucks is almost like sending cash in the mail, and I have had trouble with the other party saying they never received them in the past.