Ring Pinion Speedo Speedo Years Models Tire or Wheel Sizes Gear Teeth Adopter Geer No 48 55 1 TON lst Ser 7 50 20 8 und 10 ply 37 6 1565812 3689121 48 55 1 TON lst Ser 10 00 18 12 ply 37 6 1565813 3689121 54 55 2 TON w 2 SPD lst Ser 7 50 20 10 ply 8 25 20 10 or 12 ply 8 86 und None 3689121 6 7 48 55 M TON lst Ser exc D D 15 6 and 8 ply 36 7 None 3689178 55 58 ft TON 2nd Ser exc D D 15 6 50 x 16 32 7 None 3689178 55 58 TON 2nd Ser exc D D 7 50 x 17 32 7 1565813 3689178 48 55 TON D D lst Ser 7 50 17 8 ply 36 7 None 3689178 48 55 M TON D D lst Ser 7 00 17 6 und 8 ply 36 7 1565814 3689178 55 58 D D 2nd Ser 7 00 x 17 7 50 x 17 7 00 x 18 36 7 None 3689178 48 55 1 TON lst Ser 7 00 17 6 cmd 8 ply 36 7 1565814 3689178 48 55 1 TON lst Ser 7 50 17 8 ply 7 00 18 8 ply 36 7 None 3689178 55 58 1 TON 2nd Ser 7 00 x 17 8 ply 7 50 x 17 8 ply 7 00 x 18 8 ply 36 7 None 3689178 48 55 1 TON lst Ser 6 50 20 6 cmd 8 ply 7 00 20 8 cmd 10 ply 7 38 oxle ratio 38 7 None 3689178 48 55 1 TON lst Ser 7 50 20 8 cmd 10 ply 38 7 1565812 3689178 48 55 ALL w 2 SPD lst Ser 8 25 20 10 ond 12 ply 9 00 20 10 ply 8 10 cmd None 3689178 6 13 48 55 2 TON lst Ser 8 25 20 10 und 12 ply 9 00 20 10 ply 37 6 None 3689178 56 58 TON exc D D 7 x 17 5 3 2 7 None 3689178 56 58 M TON exc D D 8 x 17 5 32 7 1565812 3689178 56 58 TON exc D D 8 x 19 5 32 7 1565813 3689178 56 58 D D 1 TON 8 x 19 5 36 7 None 3689178 48 55 ALL w 2 SPD lst Ser 7 50 20 8 10 und None 3689179 6 13 48 55 ALL w 2 SPD lst Ser 10 00 18 12 ply 8 10 ond 1565812 3689179 6 13 48 55 2 TON lst Ser 53 55 1 TON lst Ser 7 50 20 8 25 20 37 6 None 3689179 56 58 1 TON 8 x 17 5 8 ply 36 7 None 3689179 54 55 TON lst Ser 6 00 x 16 6 ply 55 58 TON 2nd Ser 15 6 50 x 16 6 ply 39 10 None 3707598 56 58 TON 7 x 17 5 39 10 1565812 3707598 57 58 ALL w 4 WD 7 x 17 5 6 6 x 17 5 8 x 19 5 32 7 1565812 3745935 1 1565813 57 58 4 WD 8 x 17 5 8 ply 8 x 19 5 36 7 None 3745936 57 59 4 WD 6 50 x 16 6 70 x 15 7 x 17 5 8 x 17 5 39 10 1 None E 3745934 11565812 58 1 TON 8 x 17 5 8 p1y 58 D D 7 x 17 5 8 x 17 5 6 ond 8 ply 36 7 None 3689179 58 59 TON 6 70 15 6 50 16 6 ply 37 10 None 3752392 58 TON 7 00 17 5 8 00 17 5 37 10 1565812 3752390 59 TON 7 x 17 5 37 10 None 3752390 59 TON 15 x 5 50 37 10 None 3752390 59 Ser 3E 8 x 19 5 32 7 None 3760340 59 Ser 3E 8 x 17 5 7 50 x 17 32 7 None 3760341 59 D D 1 TON 8 x 19 5 15 x 5 50 36 7 None 3760342 59 D D 1 TON 7 x 17 5 36 7 None 3760343 59 TON 6 70 x 15 39 10 None 3707598 59 TON 15 x 5 50 39 10 None 3707598 59 4 WD 15 x 5 50 7 x 17 5 6 50 x 16 32 7 None 3760358 59 4 WD 7 x 17 5 8 x 17 5 36 7 None 3760359 59 4 WD 15 x 5 5 7 x 17 5 8 x 17 5 39 10 None 3760517 59 4 WD 8 x 19 5 7 00 x 17 7 00 x 18 7 50 x 17 36 7 None 3760358 59 4 WD 8 x 17 5 7 00 x 17 7 50 x 17 32 7 None 3760357 59 4 WD 8 x 19 5 32 7 None 3760356 60 63 Ser 10 exc 4 WD 6 00 x 16 6 50 16 6 70 15 7 10 x 15 39 10 None 3707598 60 63 Ser 10 exc 4 WD 6 00 x 16 6 50 16 6 70 15 7 10 x 15 7 x 15 5 8 x 17 5 7 00 x 15 7 50 x 15 15 x 6 44 13 None 3752390 60 63 Ser 10 exc 4 WD 6 50 x 16 7 x 17 5 8 x 17 5 7 00 x 15 7 50 x 15 15 x 6 39 10 None 3752392 Chevrolet Motor 7 General Motors Corporation