Steering vibrating during braking

[marianneland]

I did a search for my topic in the Forums Search but didn't find anything.  

 

I have a 2002 Subie Outback wagon, about 96K miles.  I'm the original owner.  Recently got the front right cv something fixed, can't remember if it was the boot or the joint.  I had taken it in for a full inspection after having driven it to Florida from Utah last year pulling a trailer.

 

Anyway, a few months after I got the CV work done, my steering started to vibrate when braking.  I am not saying it's related to the CV work.  I called the mechanic and he said it sounds like your rotors need to be turned/replaced.  I said I thought you had told me my brakes were fine, he said he didn't take them off and look at the rotors.

 

The mechanic is not really close to me, and I had decided to find a shop closer to me.  After talking to my Dad on the phone (he's in Idaho) who has been fixing his own cars for many years, he felt it shouldn't be that expensive for me to get it fixed.  I found a forum that lead me to believe it would be best to replace the rotors, rather than try to get them turned due to labor.  My Dad found a forum that indicated rotors tend to go out on 2002 Outback Wagons.

 

I went to Rockauto.com and there is a brake/rotor kit for about $75.  There is a young man on a FB group I am on that is an ASE or whatever the acronym is that does work on the side.  He works at the BMW dealership for his regular day job.

 

So my question is first:  Do we agree it's the rotors?  I have found if I brake in a certain way, it doesn't really vibrate.  But if I gently brake coming up to a light, it usually really vibrates like crazy.  It doesn't vibrate much or at all if I really firmly brake, like almost slam on the brakes.  Also, if I brake putting my foot on only the right side, for some reason it doesn't seem to vibrate.  What's up with that.

 

Anyway, just wanted to get some feed back from experienced owners...

 

Thanks

 

 

[lmdew]

Well, you in a high corrosion area.  If you are only lightly applying the brakes all the time I'd bet you have glazed them over.  Some hard braking may fix the problem.

 

Have a good Subaru shop check it.  Many things can cause what your are feeling.

[Fairtax4me]

Generally a warped rotor will cause more shaking when going fast, and will shake harder the harder you brake.

 

There are plenty of things that will cause shuddering or shaking, but only a few that I think fit your description.

 

Knowing that you just had a CV axle serviced, I'm inclined to think this is related to that. Something you can easily do on your own is make sure the lug nuts are tight. Get the lug wrench out of the trunk. If you can turn them at all with that stumpy thing, (righty tighty) they're probably too loose.

 

Second thing, if you feel like getting the jack out of the trunk too. Jack up the car so the front wheel (the side which the CV was worked on) is off the ground. Grab the tire at 9 and 3 o'clock and push/pull alternately to see if you can rock it back and forth. Try the same at 12 and 6. It should feel pretty solid both directions. If it moves a bunch and you get a clunking kinda sound, something's loose.

I would be willing to be the wheel bearing is loose. Possibly due to a loose axle nut. This will cause play in the wheel in all directions. It can also cause wobbling of the wheel on light application of the brakes as the brakes try to pull the wheel back to straight. On heavy brake application the brakes clamp down tight on the rotor and will bring the wheel straight and hold it there. Once the brakes are released the wheel will be loose again.

[marianneland]

Generally a warped rotor will cause more shaking when going fast, and will shake harder the harder you brake.

 

There are plenty of things that will cause shuddering or shaking, but only a few that I think fit your description.

 

Knowing that you just had a CV axle serviced, I'm inclined to think this is related to that. Something you can easily do on your own is make sure the lug nuts are tight. Get the lug wrench out of the trunk. If you can turn them at all with that stumpy thing, (righty tighty) they're probably too loose.

 

Second thing, if you feel like getting the jack out of the trunk too. Jack up the car so the front wheel (the side which the CV was worked on) is off the ground. Grab the tire at 9 and 3 o'clock and push/pull alternately to see if you can rock it back and forth. Try the same at 12 and 6. It should feel pretty solid both directions. If it moves a bunch and you get a clunking kinda sound, something's loose.

I would be willing to be the wheel bearing is loose. Possibly due to a loose axle nut. This will cause play in the wheel in all directions. It can also cause wobbling of the wheel on light application of the brakes as the brakes try to pull the wheel back to straight. On heavy brake application the brakes clamp down tight on the rotor and will bring the wheel straight and hold it there. Once the brakes are released the wheel will be loose again.

Thanks for the insight.  That is interesting information.  Now you have me thinking, sometime after I got the CV axle worked on by the mechanic, I had Costco put Nitrogen in the tires (I'm getting 23 mpg now) and I think I can take it to them and ask them to confirm that the tire(s) are not loose and tell them what I am experiencing.  I'll let you know.