73k miles. Stock transmission and clutch. Religiously maintained. Got into my car this morning to go to work and I physically couldn't shift into any other gears, no matter how much force I used. I just drove it two days ago. It was 16'F this morning, but I have driven the car perfectly fine all the way down to -20'F with -70'F wind chills. I'm thinking temperature isn't much if a factor. My transmission fluid (I used the official GM fluid) is about a year old with maybe 10k miles on it. Any ideas? Car started up and ran fine. First and second engage just fine. Just can't shift into third, fourt, fifth, or reverse to get out of my driveway.

 

Check the cable connections on top of the transmission.

 

09 SS/TC 141k stock clutch/trans. For the last 3 winters, whenever the temp gets down to below 20 F, especially if we've had precipitation (rain or snow) recently, my shifter gets completely stiff. When I first start the car it literally won't move at all. After sitting there for a few minutes I'm finally able to gently yank it out of first back to neutral. Once its in neutral there is still no play left or right. After a few more minutes sitting there I begin to get some play left and right and (with the clutch in of course) I start to try and run it through all the gears. The gears literally feel frozen? All in all it usually takes a good 10-20 minutes of sitting there and jerking the shifter around before all the gears feel loose enough to drive. 3rd and 4th are always the stiffest. This never ever happens when it's warm out or even near freezing, just when it's super super cold and recently wet/snowy. Not sure if it's a similar issue to what you're having or not, but it's been an annoying issue for me every winter.

 

Sounds like the insulatuin that is protecting the cable is ripped/worn-out , water gets inside the cable then over night it freezes over.