I've been reading about this: Has anyone truly figured out if the front wheel shake is a rotor problem or a steering column problem. I have replaced both pads and rotors and still have a shaking while braking. 2006 HHR

 

Old topic, I wish it had an answer. My 08 SS does the same thing. The steeringwheel shakes violently while braking. I also get a front end knock while hitting bumps at slow speeds

 

If the rotors are checked and are true and not warped
I am guessing steering column or intermediate shaft below it.
This was posted somewhere else.
With engine off step on brake pedal while stopped of course and move steering wheel back and forth
I notice that the non ss hhr's are much more forgiving obviously on transmitting the road to the driver.
Super low profile performance tires on the ss along with the suspension just magnifys this issue.
If you have a warranty have the dealer check it out.

 

Fyi
Just had my Steering column replaced its like a whole new car.
Not sure if thats your problem but a good tech could check it out.

 

I have a 2008. Same clunks , same steering rattles, same front shudder when brakes applied!! I just bought drilled and slotted rotors and ceramic pads on ebay. While installing, I found one caliper pin frozen on each side. Maybe this is causing the shudder???? Anyone else found this?

 

The shudder is from the caliper pins being frozen causing uneven wear and most likely hot spots on the rotors so they warp. When I had the HHR on jack stands, I had a helper start up it up, put foot on brake, put in gear, let up brake and allow the wheels to turn freely then apply the brake. This showed me that the calipers were potentially warped and saw that the caliper was not actuating as it should.

I had two caliper pins that were frozen. The top ones on each side. fortunately mine were not bad, cleaned them up. Polished with emery cloth to smooth the pin and the pin hole, then greased with a good grade of assembly lube that contained moly and graphite. Replaced brake hardware with new clips and and pin boots. Cleaned all parts and painted the rotors and bracket with a high temp caliper paint so they look good. Replacing the pins and the caliper bracket is not expensive if needed. Put new brake back plates TSB number 08-05-23-003 (only $7 and some change each), new rotors and good pads. Not quite in the order as listed. All is good.

 

Does anyone know why there are 3 different length sway bar links listed under part suppliers? All the HHRs are about the same.

 

The short answer is, because they are Not all the same. This topic has been discussed many times on this forum. Use the search function and you should find a bunch of threads on the subject.

 

Shuddering while braking can also be attributed to wheel bearings (front and/or rear). Don't forget to check the, especially the rear hubs nobody ever thinks about them.

 

I too! I replaced rotors w/drilled and slotted and ceramic pads. Also one caliper pin was frozen on each side. Freed the pins, installed parts and they are good!