all this post does is to show that there is just as much BS on AULRO as the Genuine article. Quite obvious that some of the posters here have no idea what they are talking about.
one of the answers might be correct if the Discovery had rear leaf suspension, which it obviously does not.
either your chassis is bent or you have an incorrect trailing arm fitted ( measure them - they should be the same length) the washers have been put there to try and cover up the issue, Butcher mechanics more like it.
check it out & see if I'm one of the BS posters

