What's to break????? (other than hitting the TV while backing

) It's not like anyone would get on the freeway with it.
The OP says he's backing straight up. Even in my wildest imagination, I can't see the harm (other than hitting the TV while maneuvering:new_bdays).
When he said backing it straight into the barn, I was visualizing a path that was not paved. All the barns I know about are in pastures.
I have never seen a barn that was paved, along with the access path to it.
But, I certainly have not been to every farm in the US.
Perhaps my interpretation of barn is incorrect.
A few web searches for the definition of barn yields things like:
- an outlying farm building for storing grain or animal feed and housing farm animals
- an agricultural building used for storage and as a covered workplace. It may sometimes be used to house livestock or to store farming vehicles and equipment. Barns are most commonly found on a farm or former farm.
- an agricultural building with large, usually sliding doors, prominent roofs, and predominantly open spaces on the interior, primarily used as storage buildings for hay, grains, and farm equipment and shelters for livestock.
I can not imagine a barn that was originally housing cattle having a smooth surface. In the winter, the dirt road to the barn might be a little slimy.