diff size

[Phantom]

G'day all ,
                    This is probably a dumb question but how can i tell what size diff i have in my car ?
                               Cheers Rusty

[mcl1959]

Grey motor diff as standard in FX through to EJ was 3.89:1
These have a uni joint which has bolts which screw into the uni.  There is no ratio identifying mark on the outside of the diff.
All red motor diffs are identifiable by having a rear uni which has a U bolt and nuts which hold them to the rear flange.
The circular plate on the rear flange has the ratio stamped in it.
It is possible that you have a red motor diff with grey flange on it which would mean that you cannot identify its ratio without taking it out of the car since the ratio is also stamped on the crown wheel.
Ken

[Phantom]

Thanks Ken , the diff does have u-bolts to attatch the uni to the flange
                  Cheers Rusty