Hi Marc, I changed the power steering rack and power steering pump on my 2wd Saff a few years back and I was very suprised at the difference it made. Much lighter than it was before with a nice direct feel to the steering. I had got used to how it felt for over 20 years so for me it was a very good upgrade!! I run mine with lowered suspension, Hi-Spec big brake conversion,17inch ET35 alloys with 215/40/17 tyres. Have you fitted a new/reconditioned power steering rack or pump to yours as the problems you are having to me seem to point to one or both items having a fault?