Garmin Settings

Roll Servo
Servo Direction = Normal
Max Torque = 75%
Servo Gain = 0.80
Fine Adjust Time = 0.20
Fine Adjust Amount = 0 (disabled)

Pitch Servo
Servo Direction = Reversed (at least in this test plane, probably all)
Max Torque = 100%
Servo Gain = 2.50
Fine Adjust Time = 0.20
Fine Adjust Amount = 1

Pitch Gain
Min Airspeed Limit = 70 kt
Max Airspeed Limit = 180 kt
Vertical Speed Gain = 1.40
Vertical Accel Gain = 1.00
Airspeed Gain = 1.35
Airspeed Accel Gain = 1.00

Yaw Servo
Servo Direction = Normal
Max Torque = 100%
Servo Gain = 1.50

Manual Electric Trim
Airspeed Threshold = 80 kt / 150 kt
Roll Trim Motor Speed = 100% / 50%
Pitch Trim Motor Speed = 100% / 50%

Source: Garmin recommended autopilot settings