Transmission shifting hard when cold

Hello,

The hard shift when cold is a very common issue with the 4L60E.
Typically the hard shift will be shifting from 1-2.
But when the transmission and the fluid warms up, it will get smooth.
There is not a simple fix out there for it.
Make sure that the fluid is at the correct level and the fluid condition is good.
When you check the fluid you want to make sure that the engine is at operating temperature and the vehicle is level. Check the fluid with the engine running.
I have attached the factory recommended procedure for your reference.

https://www.2carpros.com/articles/automatic-transmission-problems

Let me know if you have any questions.

Thank you.