I'll offer what is going on with mine 2008 LS
Using the directional for left turns sometimes I feel resistance when trying to engage the detente. When that is the case I don't force it I hold the lever manually. After making a few turns and using it later it operates normally. Then it will reoccur randomly and I do the same procedure.
I'd expect it is something broken that at times moves and interferes with the switch holding the on position.
Just for what's it's worth.
Maybe seeing your results posted will help me down the road when it causes permanent problems.
Possibly disassembly now will help prevent more costly repairs later?

 

Have a good read thru this thread

https://www.chevyhhr.net/forums/how-...ts-pics-37992/

 

Yup I have had this problem with the right signal not cancelling after a turn.
I think it was caused by pushing the lever the opposite way while turning the wheel, cheap plastic bit inside.
I havent bothered fixing mine, but made even more annoying in my case due to aftermarket stereo without the chimes and signal ticks.

 

This was a handy fix for some of us - a problem with the spring inside the turn signal housing - https://www.chevyhhr.net/forums/how-...ts-pics-37992/

 

The signal canceling issue is intermittent with mine = mostly not canceling right turns, and then canceling randomly off and on with left turns. I saw these YouTube videos (Below) regarding a fix by disassembling and reassembling the actual part. Does anyone feel this is successful, or has been proven/disproven to be effective. I believe it's not broken, as it usually works, but seems that the spring could be just going bad. I had a similar issue to fix with my sister's Equinox. But, I don't know if the part is the same or similar, though at first glance of the pics, it seems to be close to the same.

 

I just purchased another unit from Rock auto, it only took 5 minutes to replace and problem solved. Not expensive at all....if your time is worth anything.

 

Are they Ebay or private website? Looking forward to doing this.

 

Ok, I found the page, but there are multiple items. Which part# did you order for yours?

 

I bought the one on the top of your list, however mine is the 2008 2LT which should be the same for yours....I think.

 

I agree with you 100%. For that cost, It's definitely worth changing the whole thing. Appreciate it!