I was going to post on another members thread, but didn't want to hijack it. I too am experiencing a 40-60mph brake shake. I just did a pad and rotor (not GM) replace last summer (about 8000 miles ago). Pads still have plenty of material on them, but I noticed this week I'm getting a shake when braking at speeds about 40mph. With all the other front end noises I've had lately, I'm starting to wonder if this shake is a brake problem or LCA problem. Over bumpy terrain (we have a lot of post winter potholes) the front suspension just seems noisy to me. If it is the LCAs, would I only get the brake shake at certain mph or all the time? I don't feel anything at lower in-town speeds. I want to pull the wheels this weekend hopefully and do some investigation. If I put the car up on stands and pull the wheels, should I be able to feel or see if the control arm bushings are worn? Will there be visible "play" in the suspension components?

 

Pleas give the SEARCH box a try. This is THE most posted problem, even more than the recall.

The title of your thread produced 153 thread links. Most of them providing exactly what you are seeking.

 

I did "give the search box a try" and also read about the LCAs. I may have one issue or two here. I'm asking for opinions on the problem based on my "symptoms."

 

"If it is the LCAs, would I only get the brake shake at certain mph or all the time?" - who knows - and I doubt if anyone here will be doing a study to determine that.

If you suspect the LCA's - just crawl under the car and eye-ball the rear LCA bushings. If the bushings are shot, it will be pretty apparent by using a screwdriver or such, to pry against the LCA and the frame mount and look for "slop".

Trying to diagnose something like this over the internet is pretty difficult - about all anyone here can do is suggest a list of things to check. Ball joints, brake rotors, hubs, lower control arm bushings, ball joints, bent rims etc..

You mention noises (plural) - yeah you may have multiple problems. In your search you may have noticed that some have found that front suspension noises were caused by struts, strut bearings, sway bar links, sway bar mount bushings.

But understand that garages and dealers have a difficult time determining the cause of the noises, and often replace several parts before they find the right one. So diagnosing it in person is not easy - and giving a solid answer over the internet is almost impossible.

 

Thank your Whopper for your incite. Yeah, I've found that it can be many things. That's why I was hoping that replacing the rotors to none-GM parts would help. I've already done the sway bar links...twice...with Moogs. The second time, I told the shop I had already had them replaced the previous summer, but they replaced them again under Moogs warranty so I didn't have to pay for parts and labor costs were minimal. Of course, it didn't solve the problem. The steering column issue that can cause a noise was replaced under GM warranty in 2010. I'm going to have to pull the wheels and crawl under there and have a look. From what I gather, if I do need to replace the LCAs it seems pretty straightforward and I should be able to do it myself. This is a 2007 HHR 2LT Fall Special and I just rolled over 77,000 miles last nite.

 

Cool - it's not a super hard job - but it can take a wee bit of muscle to get things to line up. But it is a one man job.

There is a write-up in the How-To section on replacing them. One can just replace the bushing, but a lot of people just do the whole LCA which includes the bushings which makes it easier as the bushings have to be pressed out if they are being replaced.

 

My opinion on your symptoms is: you should read a lot of threads from the search links to get an idea of what other people have heard/felt and what was done to remedy. I scanned the first page and saw references to just about everything it could be.

Written descriptions of sounds, noises and vibrations are no good for diagnosing, for instance I have read at least 10 different descriptions of a problem that was cured by replacing a hub. And then there was the case of the guy that went on and on about a noise under his hood, no suggestion made worked, he eventually found a Dr.Pepper cap lodged in his alternator (my guess had been a Pepsi cap).

I you were sitting in the parking lot next to me, I might be able to give a better response.

You asked for opinions. That's mine, with an explanation and no sarcasm and no criticism. Just one bit of humor.

 

Whopper,
I saw that post in the how-to section. Seems pretty straightforward. Also checked out a video on youtube that was very general but gave some good info. I wondered about the bushings, but I saw some posts on here that said you could change them, then others that said you couldn't. I figured best to just replace the whole arm if the bushings are belly up.

Donbrew,
Thanks for you opinion.

 

Yup, those rear bushing can be replaced, but you either need a press of some sort to press them out, and install the new ones (or a huge vice). The bushings are quite cheap - between $8 - $30 depending on the source. But most people I think have just been buying new ones like what I did from autozone, that came with both bushings AND a new balljoint.

I now have the option of installing a new bushing in the old ones if the need arises.

Keep us posted on what you find.

 

If you end up replacing the LCAs you might want to do struts right away. My theory is that the bushings go bad and put stress on the struts causing them to fail prematurely.

Also, if you replace the entire LCA it goes a lot faster with an air impact wrench. Particularly with the long bolt in the back that goes into the subframe.