How many springs are there? Do they detach from the main frame easy enough (to see how the seat looks/feels with 1 spring omitted) ?
what was the steering rack problem? mines started to have a little creak if i turn at a stand still but is fine whilst moving, wasn't sure if it was that or something elsecheeky git im only 9 stone, Do love burgers though! If its expensive will just have to put up with it. It was last on my list after suspension knocking, springs clanging also stearing rack creaking and parcel shelf creaking all these others now fixed.