I've looked around on the internet and can't find any information about HHR transmission output shafts bearings. I'm not referring to the seals. Are the bearings replaceable while the transmission is in the car? If so, is there a tutorial anywhere about this project?

The car has a shake between 60 and 65 MPH. There's no shake in the steering wheel. Both CV axles have been replaced. Both rear tires have been rebalanced.

Is it possible that just replacing the seals will stop the shake? Any help is appreciated.

 

Did you look at the motor mount? Peep through the oblong hole in the passenger side front wheel well, if a bolt head is not centered you need a new one.
Have you checked the front and rear wheel hubs/bearings? Any perceivable end play is bad, if you want to measure it is 0.001 inch.
Loose wheel house plastic.
Loose front air dam.
Loose bumper covers.
Does this shake happen when only the rear windows are open? Known design shortcoming.
Any thing hanging under the car? plastic bags etc.
If it was a trans bearing or CV you would feel it in the steering wheel.

 

The passengers side output stub shaft there and is a kit to stabilize it, but just stop the seal from leaking.
vibrations in my experience have been related to upper engine mount as Donbrew mentioned, the transmission mounts , there are 3. Hub bearings, ball joints, tie rod ends both inner and outer, then again the lower control arm bushings can cause a shake. More a remote possibility the steering rack input shaft bearings, the intermediate steering shaft is another place to look.
Now back to transmission bearings they are there but have a very small possibility of being the culprit.

 

Quote: “Both rear tires have been rebalanced”

So. What about the front tires ?

 

Thanks. I'll check it out!

 

RE: car shows... Years ago, I was an ISCA member and had a custom Toyota 4wd in the local shows. Still enjoy looking at nice cars/trucks.