Hey there Zuksters. I have a 2004 Grand Vitara 3 door 2.0 litre wide body model. The front diff crunches when I try to put it in 4WD mode and its leaking oil tragically. The mechanic reckons it needs replacing. I spoke with a spare parts dealer and he needs the diff ratio to make sure he is sending me the right diff. Cant find the tags to tell me what ratio it is, and not able to pull it apart myself to find out... anyone know whether I have a 4.875 or 4.625 diff?
The specs on the website list the J2 but the tyre size is different to mine so thought I should check. I have 235/60/16's on mine. They are the size that came standard when I bought it... Australia based.

There are no tags on the axle that tell you the ratio.
The dealer can't look up the ratio by using the VIN?

I think it will have 4.88s if you have the auto and 4.30s if you have the manual tranny.  But better wait for someone else to confirm that, since I am not all that familiar with the newer stuff.

Or, you could jack one rear tire off the ground, put the tranny in neutral, spin it exactly 2 times while counting the number of times the rear driveshaft turns.  That will tell you the ratio.  Just under 5 revolutions will be 4.88 and just over 4.25 turns will be 4.30.