With kitchen scissors or chef's knife, cut along each side of chicken's backbone; remove backbone and trim visible fat.
Tuck wing tips behind back; flatten to 1 layer. Place in shallow casserole.
Grate orange rind and squeeze out juice; mix with vinegar, oil, thyme and pepper. Pour over chicken; cover and marinate in refrigerator, turning often, for at least 4 hours or up to 24 hours.
Reserving marinade, place chicken, skin side down, on greased grill over medium-low indirect heat. Add soaked wood chips. Cover and cook for 1 hour, turning and basting with marinade halfway through.
Transfer to direct heat; cook for 10 minutes per side or until meat thermometer inserted in thigh registers 185F 85C.
Remove to platter and tent with foil; let stand for 10 minutes before cutting into quarters.