A method of replacing an accessory drive gear comprising the steps of: removing an existing accessory drive gear from an integrated drive generator having an input shaft, a gear differential including a carrier shaft and the gear differential including a ring gear for driving a generator; said carrier shaft also connected for driving said existing accessory drive gear, said existing accessory drive gear connected for driving at least one driven gear to, in turn, drive at least one pump; and replacing the existing accessory drive gear with a replacement accessory drive gear including a gear body extending between a first end and a second end and having a plurality of gear teeth at a radially outer surface adjacent said first end, and characterized by said gear teeth having a gear tooth profile, with roll angles at points A, B, C, and D, the roll angle at A being at the maximum form diameter, the roll angle at B being 20% away from point A and towards point D, the roll angle at C being 80% away from point A and towards point D, and the roll angle at D being at the outer diameter of the gear tooth; the roll angle at A being between 17.0 and 18.5°, the roll angle at B being between 20.0 and 21.5°, the roll angle at C being between 29.5 and 31.0°, and the roll angle at D being between 32.5 and 34.0°; wherein said gear teeth extend for a width away from said first end and there being an overall axial length of said accessory drive gear from said first end to said second end and a ratio of said overall axial length to said width of said gear teeth being between 2.35 and 2.5; wherein said gear body having an inner bore with a nominal inner bore surface extending from said first end toward said second end and an enlarged channel formed from said second end to meet said nominal surface inner bore, and oil outlet ports extending through a wall of said gear body within said channel; wherein a ratio of an inner diameter to said nominal inner bore surface to an inner diameter of said channel is between 1.01 and 1.115; and wherein a diameter to an outer diameter of 4.93 cm (1.94 inches), a pitch diameter of 4.7 cm (1.85 inches), and a root diameter of 4.45 cm (1.75 inches), each with a tolerance of 0.25 cm (± 0.1 inch). removing an existing accessory drive gear from an integrated drive generator having an input shaft, a gear differential including a carrier shaft and the gear differential including a ring gear for driving a generator; said carrier shaft also connected for driving said existing accessory drive gear, said existing accessory drive gear connected for driving at least one driven gear to, in turn, drive at least one pump; and replacing the existing accessory drive gear with a replacement accessory drive gear including a gear body extending between a first end and a second end and having a plurality of gear teeth at a radially outer surface adjacent said first end, and characterized by said gear teeth having a gear tooth profile, with roll angles at points A, B, C, and D, the roll angle at A being at the maximum form diameter, the roll angle at B being 20% away from point A and towards point D, the roll angle at C being 80% away from point A and towards point D, and the roll angle at D being at the outer diameter of the gear tooth; the roll angle at A being between 17.0 and 18.5°, the roll angle at B being between 20.0 and 21.5°, the roll angle at C being between 29.5 and 31.0°, and the roll angle at D being between 32.5 and 34.0°; wherein said gear teeth extend for a width away from said first end and there being an overall axial length of said accessory drive gear from said first end to said second end and a ratio of said overall axial length to said width of said gear teeth being between 2.35 and 2.5; wherein said gear body having an inner bore with a nominal inner bore surface extending from said first end toward said second end and an enlarged channel formed from said second end to meet said nominal surface inner bore, and oil outlet ports extending through a wall of said gear body within said channel; wherein a ratio of an inner diameter to said nominal inner bore surface to an inner diameter of said channel is between 1.01 and 1.115; and wherein a diameter to an outer diameter of 4.93 cm (1.94 inches), a pitch diameter of 4.7 cm (1.85 inches), and a root diameter of 4.45 cm (1.75 inches), each with a tolerance of 0.25 cm (± 0.1 inch).