A Limmited Slip Differential Question

Jack up one tire, put it in neutral, front tires safely blocked and parking brake released. See if you can turn the jacked tire, and how hard is it. If it turns easily, either it's not limited slip, or it's completely broken. If you can turn it "with some effort" it's limited slip but may not be very good shape. On my old 70 RR 440-6, 3.54 Dana 60 there was NO WAY IN HELL you could slip a tire like I just described.

Also "in reality" clutch type limited slip does not really work as some of the flowery descriptions. REALLY what they do, is when power is applied, the wedges in there engage the clutches tightly, and they really just sort of lock the two axles together until power is relaxed some.