Depends on the transmission. Many transmission bands are not adjustable.
Check your Automatic Transmission fluid level
Put it into reverse when moving rapidly forward.
My 2001 hyundai accent has no reverse
Sounds like you need it reworked.
bad transmission
until you face a wall.
Make sure transmission fluid level is correct Bad transmission pump?
Low Transmission fluid
If the automatic transmission on a 2002 Kia Rio won't go into park and there is no reverse, there is a problem inside the transmission with the gear bands. Each gear has a separate band and sometimes they wear out. New bands need to be put in or a new transmission needs to be installed.
Put the van on the lift and drain the transmission fluid, next drop the transmission on a tranny jack and proceed to do a transmission overhaul. Reverse the proceedure to install.
its in nutreal reverse pr out of gear