Just had wheel bearing, front struts, tie rods, the control arm bushings, rotors and brake pads replaced. I have new balanced tires. My 2006 HHR starts shaking at around 90 km/h which changes into what feels like a bobbing of the passenger side tire. All this stops at 120 km/h
The problem did not exist after repairs and started suddenly. I did not drive over a curb or damage the wheel whatsoever. I wondered that the mechanic did not alignment after changing the control arm bushings. I have read here that this is needed when those bushings are replaced. Is this a alignment issue or maybe it is a tire issue? There is no sign of wear on the tire. The bobbing of tire is up and down without the steering wheel showing any sign of vibrating or pulling to one side.

 

Welcome-

If you could jack it up & spin that wheel, check for any run-out aka out of round..

Might be a tread belt broke.

 

i have noticed that hhr is really picky on the tire balance, even the tire wear is affected easily and they need rebalance.

but first check that the balancing bits are in place. if one is missing, it will cause that.

 

I'd start with who every did the work and let them take a look at it. SInce it didn't start right after the repair, but a little later on. Wheel could have thrown a weight or something.

 

I had a problem like that. I had a 60-70 mph shake in the steering wheel . It felt like it was on the drivers side. I took it to the tire shop and they moved the front tires to the rear and rear to front. I drove it and the shake was gone. Then they moved the rear drivers side to the front again and the shake was back. The tires had only about 2000 miles on them. They got me a new tire for the front and all is well. It was under warrantee,no cost... hope this helps john

 

All the above suggestions are viables for sure, but here is a little tip/thought that many do not know about or consider.

Depending on your driving habits and the useable power of the vehicle, there is a possibility that you can spin/move the tire on the wheel while making panic stops and full throttle accelerations from a stop.

I went to Costco for my last 2 sets of tires and they wisely use a gell type bead lubricant to mount and demount the tires.
They actually over use it in my opinion and that could add to the possibilty of tire spin.
I have actually had this happen in the past and the only way I knew was they had marked the valve location on the tire when they were re-mounting a leak repair.

Just keep this in mind when wondering why you had to have a tire rebalanced. Especially if the balance was OK to start and/or it was not a thrown wheel weight.

SF

 

No wonder the SS needs a balance more often, maybe getting a little slippage of the tire on the rim, never thought of that.

 

You might try marking the tire and wheel on the inside so you can tell if you have had any movement. A quick glance will tell all.

This movement could also vary by type and brand of tire depending on available traction at the time of an event.

SF

 

So right you are! My tire man told me that Michelin recomends that you wait 30-50 miles before you get your new tires balanced!

 

That sounds like a reasonable request. It just requires the extra time to go back to the dealer if you can't do it the same day.
I am somewhat Old Fashioned and conservative in many of my ways.
I also believe in the 500 mile break in period although that is very difficult when you drive the Freeways every day.
Since I live in a small town I give new tires 55-60 mph Max. for close to the 500 mile recommendation.
I my case I can take the back roads at 45mph for the first 100 miles and then just stay in the right lane on faster hiways for the rest.
It's a little demeaning when your driving slower in an HHR and a Prius passes you with a smerk on there face.

SF