Rear Axle
Driveshaft ]                                             

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1970 Differential ID Code

Click On thumbnail

Pic of driveshaft at the bottom of this page

doc_diff_id_codes.jpg (21903 bytes)

 

Plant Codes:

G = Detroit Gear & Axle

B = Buffalo NY

W = Warren MI

 

Positraction Codes:

D = Dana posi diff

E = Eaton posi diff

W = Warren Motive

 

Decode - COZO522G

                        E
COZ = 3.73 Camaro Posi axle
05 = Month: May

22 = Day: 22nd day
G = Assembly Plant: Detroit Gear & Axle
E = Posi Source: Eaton

 

 

    Posi or Non Posi

 

Gear Ratio Code
2.56:1 COA
2.56:1 COB
2.73:1 COC
Posi 2.73:1 COD
3.08:1 COE
Posi 3.08:1 COF
3.36:1 COG
Posi 3.36:1 COH
Heavy Duty 3.08:1 COI
Posi Heavy Duty 3.08:1 COJ
Heavy Duty 3.36:1 COK
Posi Heavy Duty 3.36:1 COL
2.56:1 COM
Posi 2.56:1 CON
4.10:1 COO
2.73:1 COP
Posi 2.73:1 COR
3.07:1 COS
Posi 3.07:1 COT
3.31:1 COU
Posi 3.31:1 COV
3.55:1 COW
Posi 3.55:1 COX
3.73:1 COY
Posi 3.73:1 COZ
3.07:1 CRA
3.31:1 CRB
3.55:1 CRC
3.73:1 CRD
4.10:1 CRE
2.56:1 CRF
Posi 2.56:1 CRU
Heavy Duty 3.08:1 CRH
Posi Heavy Duty 3.08:1 CRI
2.73:1 CRX
Posi 2.73:1 CRY

 

 

 

                                Positraction Casting Numbers

 

Axle                Casting Number Series    Gearing
12-bolt Passenger ED 32088 2 2.73:1 and down
  30140PM1 3 3.08:1 to 3.73:1
  EDB 30174 4 3.90:1 and up
Corvette ED 32297 PW 3 3 2.73:1 to 3.70:1
  EDB 32298 4 3.90:1 and up
8.5 corporate 410408N 3 2.73:1 and up
  410409N 2 2.56:1 and down
8.2 10-bolt ED 21118 2 2.73:1 and down
  EDB 30116 3 3.08:1 and up

 

 

 

Rear Axle Gear Ratios

 

The gear tooth ratio of the ring and pinion for example

10-41 is stamped on the pinion head or stem and

also on the ring gear. Therefore you can calculate the axle ratio.

Ring gear tooth count=41

Pinion tooth count=10

41/10 = 4.10

 

Tooth Combinations Ratio
16-41 2.56:1
15-41 2.73:1
14-43 3.07:1
13-40 3.08:1
13-43 3.31:1
12-37 3.08:1
12-41 3.42:1
11-37 3.36:1
11-39 3.55:1
11-41 3.73:1
10-41 4.10:1
9-37 4.11:1

 

 

Rear Ends

 

  1970 1970 1971-75
  10-Bolt 12=Bolt 10-Bolt
Bolt Diameter (in.) 3/8 3/8 7/16
Ring Gear Diameter (in.) 8.20 8.875 8.50
Pinion Diameter 1.438 1.625 1.625
Axle Splines 28 30 28
Overall Dimensions:      
Axle tube flange to axle tube flange 55 1/4 55 1/4 55 1/4
Between centerlines of spring seats 45 3/8 45 3/8 45 3/8
Axle shaft length 30 5/32 30 5/32 30 5/32

 

Remember if you have a posi unit to add 2 bottles of limited slip lubricant.