update
thanks for all the replies i have finally got some where with this
started of by centralising the steering box then went and got the tracking set
then i adjusted the drag link to centre the steering wheel.
spent hours trawling through various posts on here and ended up out with the ruler and measured the distance between the chassis and axle front and rear and came to the conclusion the o/s or drivers side was 20mm lower than the n/s
i then stripped all four springs back of and found that they are of equal length with from all the reading of posts on here made sense of the 20mm difference as the 200 tdi had longer springs on the driver side
so to combat this a set of 20mm alloy spacers were ordered £20 and fitted to the driver side and hey presto truck now sits level and handles in corners as good as i imagine it will
next thing is mot time next month so we will see what that throws up
thanks again every one