thats it mate next time when you under your car look if there is a lump of metal bolted to the gearbox right hand side on a normal gearbox the shaft enters the gearbox at the lenght of the sandwish plate on a oem lsd the shaft is shorter and slots in to a lump of metal thats bolted there between the shaft and box ( viscous coupling ) if your unsure upload a pic of urs wel tel you