Rear End Freezing

We are in a nasty cold snap and my rear tires are freezing up. When I back out of my driveway my rear tires allow that to happen ,but when I put it into drive the rear tires don't turn . After a few minutes ,I will try again either taking it out of 4wd and putting it into 2wd .Sometimes this works . This has only happened during this cold snap .Should I worry ? I have the truck parked in the garage now ,hoping this will help ,any ideas ?

 

parking brake froze?

 

Maybe check your differential fluid. If low, it could be frozen.

 

Don't apply the ebrake. Chock the wheel if on a slope.

 

The parking brake cables have a rubber grommet at the rear hubs. It is known to rot and rust the cable due to water getting in. The freezing is your truck telling you that you need to replace the parking brake cable. At least it's not totally rusted. Yet.

 

Maybe. We don't have pics.