Axle Ratio & Identification

Rear axle identification information is stamped on forward side of left or right axle tube on all models except Fleetwood. See Fig 1. On Fleetwood, an identification code is stamped on rear of right axletube 3" (76 mm) from differential housing or backside of right caliper support plate.

AXLE RATIO IDENTIFICATION

Application

Axle Code

7 1/2" Ring Gear (2.56:1)

8GD & 8GE

7 5/8" Ring Gear (3.23:1)

8HM

8 1/2" Ring Gear

2.56:1

⁽¹⁾ 6GK, 6GM & 6MA

2.73:1

6MF & 6YL

3.08:1

6MD, 8LA, 8LM, ⁽¹⁾ 8LN, ⁽¹⁾ 8NC, ⁽¹⁾ 8NG & ⁽¹⁾ 8NQ

3.23:1

6YE & ⁽¹⁾ 6YM

3.42:1

⁽¹⁾ 6GP & 6GS

9 1/2" Ring Gear (3.73:1)

⁽¹⁾ 4ML & 4MM

⁽¹⁾	Positive traction differential.

Fig 1: Locating Axle Ratio Codes

Courtesy of GENERAL MOTORS CORP.