Luke,
This subject is somewhere on the forum but can't find it, but I downloaded the contents last time please review the information below.
Diff Codes ( Ford Sierra Diff codes, Differential Codes, Diff Numbers, Sierra Diff )
Ford axle codes
A=3.36 B=3.77 D=3.92 F=3.842 J=4.056 K=3.31 M=3.14 N=4.29 P=3.58 J=3.62 V=3.33 Z=3.59 2=4.27 3=3.62 4=3.82 5=3.26 6=3.12 8=3.56
3,14 CW47-Pin15
3,38 CW44-Pin13
3,62 CW47-Pin13
3,92 CW51-Pin13
3,77 CW49-Pin13 6.5 inch diff
3,38 fitted to 1,6 OHC ECO 5 speed
3,38 fitted to 2,0 OHC HC
3,38 fitted to 2.3 v6 ESTATE
3,14 fitted to 1,6 OHC ECO 4 speed
3,14 fitted to 2.3 v6 SALOON
3.14 fitted to 2.3 Diesel
85GG 4006 DC --- 3.97
85GG 4006 BC --- 3.62
85GG 4006 AC --- 3.38
85GG 4006 FB --- 3.36
87BG 4006 GB --- 3.14
86GG 4006 AAA --- 3.92 LSD
V87BB 4006 BAA --- 3.62 LSD
V87BG 4006 CAA --- 3.38 LSD
85GG 4006 AAA --- 3.36 LSD
Vin plate codes for Diff ratio
Ratio Code
3.14 M
3.36 A
3.38 V
3.62 U
3.64 3
3.92 D
Hope this helps.
Regards
Mark