1998 2.5 v6 omega estate diff & diff oil

[ern8888]

my dads 2.5 v6 auto omega estate requires diff oil but the haynes manual tells us that there are two types depending on weter or not we have a limited slip diff but the metal tag on the diff has broken away is there any other way to tell witch differential we have? are there any distinguishing bits to tell them apart if so does any one know what?

[qapmoc]

Sometimes you can tell by jacking up both driving wheels so they are off the ground, put the transmission in P and then try turning one of the wheels by hand, the other wheel will try to rotate in the opposite direction and if it is a normal diff the turning should be really easy and if it is a limited slip it should be difficult to turn.
Make sure that the brakes are off and not binding or sticking which might feel the same.

[Toureman]

Find a quiet piece of road and accelarate hard letting the clutch in quickly so getting the rear wheels to spin! If your car only leaves only one black line on the road you have not got a limited slip diff.