GTO Rear axle codes

The data provided on this page is provided courtesy of Southern California Gathering of Goats car club.

Axles By Year

1964

Differential Ratio Std. Axle Code Std. Axle Sticker Code Std. Axle Code Color Safe-T-Track Sticker Code Safe-T-Track Color
3.08
D
2D
Orange
3D
Green-Yellow
3.23
K
2K
Brown
3K
Green-Brown
3.36
E
2E
White
3E
Green-White
3.55
F
2F
Blue
3F
Green-Blue
3.90
H
2H
Plain
3H
Green-Plain

The following ratios were available with heavy duty metallic brake linings.

Differential Ratio Std. Axle Code Std. Axle Sticker Code Std. Axle Code Color Safe-T-Track Sticker Code Safe-T-Track Color
3.23
L
2L
Brown
3L
Green-Brown
3.36
M
2M
White
3M
Green-White
3.55
N
2N
Blue
3N
Green-Blue
3.90
P
N/A
N/A
3P
Solid Green
4.30
N/A
N/A
N/A
N/A
Black

A sticker with the code was applied to the left brake drum.
The color code was painted on the top of the rear end and axle hubs.
The ratio was stamped on the right rear axle tube.

1965

Differential Ratio Std. Axle Code Std. Axle Sticker Code Safe-T-Track Sticker Code
3.08
D
WE
YE
3.23
K
WF
YF
3.36
E
WG
YG
3.55
F
WH
YH

The following ratios were available with heavy duty metallic brake linings.

Differential Ratio Std. Axle Code Std. Axle Sticker Code Safe-T-Track Sticker Code
3.08
G
XB
ZB
3.23
L
XF
ZF
3.36
M
XG
ZG
3.55
N
XH
ZH
3.90
P
N/A
ZK
4.33
S
N/A
ZL

A sticker with the code was applied to the left brake drum.
The code was also stamped on the axle housing directly to the right of the carrier case and below the brake line clip.

1966

Differential Ratio Std. Axle Code Std. Axle Sticker Code Safe-T-Track Sticker Code
3.08
F
WE
YE
3.23
G
WF
YF
3.36
H
WG
YG
3.55
K
WH
YH
3.90
P
N/A
ZK
4.33
S
N/A
ZL

The following ratios were available with heavy duty metallic brake linings.

Differential Ratio

Std. Axle Code

Std. Axle Sticker Code

Safe-T-Track Sticker Code

3.23

M

N/A

ZF

3.36

T

N/A

ZG

3.55

W

N/A

ZH

3.90

P

N/A

ZK

4.33

S

N/A

ZL


A sticker with the code was applied to the left brake drum.
The code was also stamped in the axle housing to the right of the carrier.

1967

Differential Ratio

Std. Axle Code

Std. Axle Sticker Code

Safe-T-Track Sticker Code

2.78

D

WC

YC

2.93

E

WD

YD

3.08

F

WE

YE

3.23

G

WF

YF

3.36

H

WG

YG

3.55

K

WH

YH

3.90

P

N/A

ZK

4.33

S

N/A

ZL


A sticker with the code was applied to the left brake drum.
The code was also stamped in the axle housing to the right of the carrier.

1968

Differential Ratio

Std. Axle Code

Std. Axle Sticker Code

Safe-T-Track Sticker Code

2.78

D

WC

YC

2.93

E

WD

YD

3.08

F

WE

YE

3.23

G

WF

YF

3.36

H

WG

ZG

3.55

K

WH

ZH

3.90

P

N/A

ZK

4.33

S

N/A

ZL


A sticker with code was applied to the left brake drum.
The code was also stamped in the axle housing to the left of the carrier.

1969

Differential Ratio

Sales Code

Non Safe-T-Track Code

Safe-T-Track Code

H.D. Safe-T-Track

2.56

C

WB

XB

N/A

2.78

D

WC

XC

N/A

2.93

E

WD

XD

N/A

3.08

F

WE

XE

N/A

3.23

G

WF

XF

N/A

3.36

H

WG

N/A

XG

3.55

K

WH

N/A

XH

3.90

P

N/A

N/A

XK

4.33

S

N/A

N/A

XM


A sticker with the code was applied to the left brake drum.
The code was also stamped in the axle housing to the left of the carrier.

1970

Differential Ratio

Sales Code

UPC Code

Non Safe-T-Track Axle Code

Safe-T-Track Code

3.07*

R

GX1

WT

XT

3.08

F

GU4

WE

XE

3.23

G

GU5

WF

XF

3.31*

T

GX2

WU

XU

3.55*

W

HO2

WH

XH

3.90

P

GU8

N/A

XK

3.90

-

-

WK

YK

4.33

S

GU9

N/A

XM

4.33

-

-

N/A

7N


* These ratios were offered with the optional 12 bolt rear end(455 only)
A sticker with the code was applied to the left brake drum.
The code was also stamped in the axle housing to the left of the carrier.

1971

Differential Ratio

Non Safe-T-Track Axle Code

Safe-T-Track Code

3.07*

WT

XT

3.08

WE

XE

3.23

WF

XF

3.31*

WU

XU

3.55

WH

XH

3.55*

WV

XV

3.90

N/A

XH

3.90*

N/A

XK

4.33*

N/A

XM


* These ratios were offered with the optional 12 bolt rear end.
A sticker with the code was applied to the left brake drum.
The code was also stamped in the axle housing to the right of the carrier.

1972

Differential Ratio

Non Safe-T-Track Sticker Code

Safe-T-Track Sticker Code

3.07*

WT

XT

3.08

WE

XE

3.23

WF

XF

3.31*

WU

XU

3.55

WH

XH

3.55*

WV

XV


* These ratios were offered with the optional 12 bolt rear end.
A sticker with the code was applied to the left brake drum.
The code was also stamped in the axle housing to the right of the carrier.

1973

Differential Ratio

Non Safe-T-Track Sticker Code

Safe-T-Track Sticker Code

3.08

AD

CD

3.23

AE

CE

3.42

AJ

CJ


A sticker with the code was applied to the left brake drum.
The code was also stamped in the axle housing to the right of the carrier.

1974

Differential Ratio

Non Safe-T-Track Sticker Code

Safe-T-Track Sticker Code

2.73

JA

JM

3.08

JB

JN