can anybody tell me how to identify what ratio a diff is. (I have got the idetification off the metal tag on the diff and wondered if there was anywhere that I can reference this to see what the ratio is)

http://www.locostbuilders.co.uk/viewthread.php?tid=85080

This may be of use. If not, post up what the tag says and someone on here will hopefully tell all!

ATB

Previous posts on this subject have said to rotate the output shafts together and the number of rotations of the input shaft will give you your ratio - or be close enough for you to know which of several ratios it is.

the codes on the metal tag are as follows
83BG JD 392
4A 0J11 1558

code that is on diff casing is
83BG 4033 BA

3.92 hows that what you wanted ?

Mike

Hi,
A friendly man at the local ford dealer let me use his microfiche machine and I've managed to get all the part numbers, FINIS numbers, exploded diagrams etc for Sierra, Granada and Scorpios. I'm putting together everything I've found at www.super7thheaven.co.uk
Hope that helps - It's a work in progress