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GM RPO Axle Codes

To find the axle gear ratio of any GM vehicle, locate the RPO sticker (typically located in the glove box) and write down any codes starting with F, G, or H. Then, find those codes in the table below.

GM RPO Axle Codes

GM RPO Axle Code Notes

These RPO codes are used to idicate a specific type of differential and/or ring gear size. Not all applications will have one of these codes but when they apply, they will be listed in addition to an axle code found in the main RPO axle code list below.

RPOAxle Type
G76 Rear Axle (Posi)
G80 Positraction
G81 Positraction (Rear)
G86 Limited Slip (Rear)
G87 8.5" Ring Gear
G89 7.5" Ring Gear

GM RPO Axle Code List (F)

The following is a complete list of GM RPO axle codes for Chevy and GMC vehicles starting with the letter F.

RPOAxle TypeRatio
F16 Transaxle 2.53
F17 Transaxle 2.84
F18 Transaxle 2.65
F25 Transaxle 3.32
F29 Transaxle 2.82
F36 Front Axle 2.19
F45 Front Axle 2.93
F47 Front Axle 2.73
F57 Front Axle 3.15
F62 Transaxle 2.39
F67 Transaxle 3.19
F68 Transaxle 3.45
F75 Transaxle 3.18
F77 Transaxle 3.73
F79 Transaxle 2.97
F82 Transaxle 3.23
F83 Transaxle 3.05
F90 Front Axle 2.73
FA0 Rear Axle 5.77
FA1 Rear Axle (2 Speed) 4.88/6.94
FA2 Rear Axle (2 Speed) 4.88/6.94
FH5 Transaxle 2.81
FH6 Front Axle 3.64
FH7 Transaxle 4.12
FH8 Front Axle 2.40
FH9 Transaxle 2.60
FJ1 Front Axle 4.18
FJ2 Front Axle 3.74
FJ3 Transaxle 3.35
FJ4 Front Axle 4.53
FJ5 Front Axle 4.19
FJ7 Front Axle 4.56
FP0 Transaxle 2.55
FP1 Transaxle 2.72
FP2 Transaxle 3.58
FP3 Transaxle 2.73
FP4 Transaxle 2.69
FP5 Transaxle 2.95
FP6 Transaxle 3.54
FP7 Transaxle 3.73
FP8 Transaxle 3.54
FP9 Transaxle 3.54
FQ2 Transaxle 3.48
FQ3 Transaxle 2.86
FQ4 Transaxle 3.57
FQ6 Transaxle 4.12
FQ8 Transaxle 2.96
FQ9 Transaxle 3.21
FR2 Transaxle 2.93
FR3 Transaxle 3.69
FR6 Transaxle 3.84
FR7 Transaxle 3.95
FR8 Front Axle 4.17
FR9 Transaxle 3.29
FV0 Transaxle 3.67
FV1 Transaxle 3.72
FV2 Transaxle 4.18
FV3 Transaxle 3.11
FV4 Transaxle 3.71
FV5 Transaxle 4.19
FV6 Transaxle 4.24
FV7 Transaxle 4.29
FV8 Transaxle 4.31
FV9 Transaxle 4.53
FVO Transaxle 3.67
FW2 Transaxle 3.06
FW3 Transaxle 4.02
FW4 Transaxle 3.89
FW5 Transaxle 4.10
FW6 Transaxle 3.42
FW7 Transaxle 3.83
FW8 Transaxle 4.28
FW9 Transaxle 3.43
FWS Transaxle 4.10
FX1 Transaxle 3.94
FX2 Transaxle 2.66
FX4 Transaxle 3.35
FX8 Transaxle 3.61
FY1 Transaxle 2.36
FY3 Transaxle 3.79
FY5 Transaxle 3.52

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GM RPO Axle Code List (G)

The following is a complete list of GM RPO axle codes for Chevy and GMC vehicles starting with the letter G.

RPOAxle TypeRatio
G11 Transaxle 2.56
G44 Rear Axle 3.07
G72 Rear Axle 2.14
G75 Rear Axle 3.62
G82 Rear Axle 4.56
G84 Rear Axle 4.10
G90 Rear Axle 3.15
G91 Rear Axle (HWY) 3.08
G94 Rear Axle 3.31
G96 Rear Axle 3.55
G97 Rear Axle 2.73
GH0 Rear Axle 3.54
GH2 Rear Axle 2.29
GH3 Rear Axle 2.77
GH4 Rear Axle 2.92
GH7 Rear Axle 2.73
GJ1 Rear Axle 5.38
GJ2 Rear Axle 5.13
GK7 Rear Axle 4.78
GK8 Rear Axle 4.33
GK9 Rear Axle 4.63
GL0 Rear Axle 5.13
GL3 Rear Axle 6.17
GM1 Rear Axle 2.59
GM2 Rear Axle 3.44
GM3 Rear Axle 3.45
GM4 Rear Axle 3.67
GM5 Rear Axle 3.89
GM6 Rear Axle 4.22
GM7 Rear Axle 3.68
GM8 Rear Axle 2.56
GN9 Rear Axle 4.11
GS1 Rear Axle 2.73
GS3 Rear Axle 3.73
GS4 Rear Axle 3.70
GS5 Rear Axle 4.11
GS6 Rear Axle 4.56
GS8 Rear Axle 3.94
GT1 Rear Axle 2.56
GT2 Rear Axle 2.29
GT4 Rear Axle (5X1) 3.73
GT5 Rear Axle (GT8) 4.10
GT7 Rear Axle 3.33
GT8 Rear Axle (GT5) 4.10
GU1 Rear Axle 2.41
GU2 Rear Axle 2.73
GU3 Rear Axle 2.93
GU4 Rear Axle 3.08
GU5 Rear Axle 3.23
GU6 Rear Axle 3.42
GU7 Rear Axle 2.77
GU8 Rear Axle 3.90
GU9 Rear Axle 3.91
GV0 Rear Axle 3.55
GV1 Rear Axle 2.73
GV2 Rear Axle 5.83
GV3 Rear Axle 3.08
GV4 Rear Axle 3.36
GV5 Rear Axle 3.55
GV7 Rear Axle 4.11
GV8 Rear Axle 2.72
GV9 Rear Axle 4.25
GW2 Rear Axle 2.56
GW3 Rear Axle 2.56
GW4 Rear Axle 3.31
GW5 Rear Axle 2.73
GW6 Rear Axle 3.27
GW8 Rear Axle 4.10
GW9 Rear Axle (GU3) 2.93
GX1 Rear Axle 3.70
GX2 Rear Axle 3.07
GX3 Transaxle 3.33
GX4 Rear Axle 3.75
GX5 Rear Axle 4.09
GX6 Rear Axle 3.53
GX8 Transaxle 3.74
GY2 Rear Axle 3.31
GY3 Transaxle 4.29
GY4 Rear Axle 4.53
GY5 Front Axle 3.65
GY7 Transaxle 4.18
GY9 Rear Axle 4.31
GYS Transaxle 3.65

GM RPO Axle Code List (H)

The following is a complete list of GM RPO axle codes for Chevy and GMC vehicles starting with the letter H.

RPOAxle TypeRatio
H01 Rear Axle 3.07
H04 Rear Axle 4.11
H05 Rear Axle 3.73
H12 Rear Axle (Eaton 21065S) --
H42 Rear Axle 6.17
H43 Rear Axle 5.43
HA3 Rear Axle 5.29
HC4 Rear Axle 4.56
HC7 Rear Axle (7,500 Lbs.) 2.38
HC8 Rear Axle (Truck) 3.21
HC9 Rear Axle 5.13
HE3 Rear Axle (3,500 Lbs.) 3.07
HE4 Rear Axle 3.40
HF7 Rear Axle, (Dana 70) 4.56
HF8 Rear Axle 4.88
HJ1 Rear Axle 4.55
HJ2 Rear Axle 5.86
HJ3 Rear Axle 4.75
HJ4 Rear Axle 6.50
HJ5 Rear Axle 5.57
HJ6 Rear Axle 4.78
HJ7 Rear Axle 4.88
HK1 Rear Axle 2.87
HK3 Rear Axle 6.14
HK9 Rear Axle (10,000 Lbs.) 5.86
HO4 Rear Axle 4.11
HO6 Rear Axle 4.63

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Data is accurate to the best of our knowledge and is offered as-is with no guarantee.

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