1971 Chevelle Rear Axle Identification
The rear axle identification code consists of at least a two letter prefix indicating the gear ratio, a letter for the manufacturer's idendity, and three digits indicating the day of the year from January 1 and other codes as necessary. The identification code should be stamped on the bottom or front left or right axle tube either adjacent to the carrier housing or about 8" - 10" inboard from the backing plates.
Example: CHC0642E decodes to CHC ~ 2.73 Positraction, 064 ~
day of year starting with January 1 (the 64th day being
March 5), Chevrolet, 1 or 2 ~ shift (if
present), - ~ no Positraction, p ~ Positraction, E ~ Eaton Positraction
B = Buick, O = Olds,
C or G = Chevrolet, K or M = McKinnon Industries, or P
= Pontiac.
Casting Numbers:
12-Bolt Casting #3969278
10-Bolt Casting #3969277
| Prefix | Axle Ratio |
| GD | 2.73 ~ Positraction |
| GF | 3.08 |
| CH | 2.73 ~ Positraction |
| GA | 2.56 |
| GC | 2.73 |
| GG | 3.36 |
| GB | 2.56 ~ Positraction |
| GI | 3.36 ~ Positraction |
| KD | 2.73 |
| CW | 3.31 |
| CF | 3.31 ~ Positraction |
| RU | 3.31 |
| RV | 3.31 ~ Positraction |
| RW | 4.10 |
| GH | 2.73 |
| GN | 3.08 |
| Assembly Month - 1st and 2nd numbers | |||
| Number | Month | Number | Month |
| 01 | January | 02 | February |
| 03 | March | 04 | April |
| 05 | May | 06 | June |
| 07 | July | 08 | August |
| 09 | September | 10 | October |
| 11 | November | 12 | December |
Assembly Day - 3rd and 4th numbers
01...31
|
Rear Axle Assembly Plant - 5th letter |
|
| Code | Assembly Plant |
| B | Buffalo ~ New York |
| G | Chevrolet Gear & Axle |
| W | Warren ~ Michigan |
| K | McKinnon Industries |
CH ~ Positraction 2.73, March 5 (64th day of year), 2nd shift, Eaton
Positraction
KD ~ 2.73, K ~ McKinnon Industries, January 11th (11th day of year)
