Are you sure it's a gear-ratio issue and not a torque converter clutch problem?
The converter clutch is locked-out if the computer senses misfire.
'97 K2500 7.4L. I "fixed" my transmission and my engine misfire by replacing a single cracked spark plug.
The converter clutch is locked-out if the computer senses misfire.
'97 K2500 7.4L. I "fixed" my transmission and my engine misfire by replacing a single cracked spark plug.