Jack one front wheel up off the ground and try turning it. If you have LSD you wont be able to turn the wheel when the other side front is on the ground. Also when both are up in the air, when you turn one side, the other will turn too. seems like a lot of hassle to find out lol,take it to a car park drive it in a circle when it is clicking hold in the clutch when the car is going round and if the car is still moving round and the clicking noise has stopped then you have an lsd if the noise is still there with the clutch pressed and you still going round then your c.v joint has gone.