HI
I have a Sierra Diff in my garage which I always assumed was a 3.62 but after researching the code I think it might be a 3.92 just want to be accurate when I list it .
Could someone check the codes for me please and confirm it
Ta
Its a
83 BG 4006 JD
A 392 8E30

3.92 it's in the code. 392

Push in shafts 3.92 7" non lsd possible....

hi mate i had the same prob as the code tag is the easyest thing to rust ..
i opened up the diff and on the big main cog there will be the ratio stamped in it some were its kinda small but all sierra diff have got them ... i found out mines a 3.14
hopley89

hi mate i had the same prob as the code tag is the easyest thing to rust ..
i opened up the diff and on the big main cog there will be the ratio stamped in it some were its kinda small but all sierra diff have got them ... i found out mines a 3.14
hopley89

ratio were written in the first line end

If you have driveshafts or stubaxles handy you could put them in, turn them and count the number of turns the input shaft does. Saves removing all the back plate.

the tag with the code can be hard to read due to the rust and is easy swapped from one diff to another


so unless you sure its not been messed about with I'd always double check by taking the back cover of - that way you'll know for sure what ratio it is and if its an open diff or LSD

its only a few bolts and a bit of instant gasket and some new oil
(I'm assuming you'd drain the oil for postage anyway or change it before fitting to a car)

heres one I did earlier:

Thanks for that guys
Im fairly sure its a 3.92 open diff
Which is enough information,with some photos
Ebay next !

Ta

I took this tonight 6# 3777 3.62


Description

Is it an LSD? It does not spin freely like an open diff however I would have expected more slip.