I got in my car this afternoon to run an errand and heard it making an unusual sound. It sounded like a wheel bearing going out but wasn't coming from any of the wheels. From listening, it sounds like it is coming from the transmission. When I slow down from a speed of about 30, I hear a "slapping" sound that's like a belt has broken or slung off a pulley. When i put the car in reverse and let it idle backwards, it jerks pretty good until I give it a little gas.
I have no idea what it could be but I feel like its in the transmission. I might take it to The local Chevy dealership but they might blame it on the 18's and void the warranty

 

can't blame the 18's when they offer them on other like cars....

 

That's what I was thinking but there's no telling what kind of crap my local dealership will try to feed me

 

Sorry to hear about the problem, please keep us in the loop, ok?

 

Well, the jerking is gone but the noise isn't. I also noticed a new noise too. It seems like a soft grinding sound coming from my front driver's side wheel. Sounds like I need to change the pads on that side but I only hear it when I'm accelerating...

 

You,ve posted this problem over 2 days time.QUIT driving until you get it looked at! As a former mechanic,I can say,"it won't fix itself". If you keep driving the car you will do more (and costlier) damage.By your description it's really hard to pin point a diagnosis.(brakes,cv joint,transmission:could be one of those or something else)My advice:Tow it to your repair shop.DON"T drive.

 

Got in it this morning to see if anything had changed. The jerking is back and now it sounds like a CV axle popping. I got it towed to the dealership this morning and noticed a puddle of tranny fluid when it was moved. Hopefully whatever it is will be covered under warranty...

 

Just thought Id update this. I got a call from the service manager at the local dealership last night about my HHR. He told me that "apparently something had came apart inside my transmission and knocked a hole in the tranny case"

I went up there this morning to pick up my loaner and saw the 1/2" hole in the side of the tranny. Hopefully they'll be able to get my car back before christmas