So my standard el falcon has lowered springs and is on pedders low ryders in the rear and an lsd diff which im unsure which model it was off, (was the whole diff not just the centre. and the other week when I was changing my rear brakes I noticed the trailing arms bushes looked pretty old. Also occasionally the car makes a knock like rattle in the rear suspension has always I originally had a small look at it but then forgot all about it ( as I usually have loud music going and couldn't hear it over the exhaust really anyway. but when I did the brakes and noticed the trailing arms, it got me thinking about the trailing arms. then I had a look yesterday and it looks like the trailing arm has been rubbing along side the rear spring seat. I haven't touched anything in the rear suspension. this was all done by a previous owner. Maybe when the diff was put on it should have different trailing arms?