The adjustment as Jim points out is around #6. It will take a major misadjustment so be sure the cable pulls and springs back easily and completely when you have the cable end loose.
Also be sure that the electric kick down isn't energized. I usually do this very simply by disconnecting the kick down solenoid (at right rear of trans). The wire should just pull out of the solenoid.
Bosch Master, ASE Master, L1
33 years MB technician