Why do transmissions shift harder with a cold running engine?
My standard transmission, when driving away with a cold engine and shifting into 2nd I get a “clunk” sound rather than a nice smooth disconnect like I do when it warms up. Why ? Autos seem to shift harder when cold too.
Think about the way your body feels when you first get out of bed. Once the circulation begins you feel better right?
Your vehicle components work similar.
The fluid in the transmission is thick and stiff when cold. Often you can replace the original fluid with a synthetic (more expensive fluid) that will eliminate most of the problem. It may even allow the transmission to last longer.