Hi G.
I tent to agree with Tony that the issue is almost certainly in the power assisted steering.
The unit is operated by hydraulic pressure from the pump and actuation valves that sense movement from the column.
If a fault exists in the Powered Steering then the effect would be exactly as you describe.
No 'notch' issues - etc - Notch issues are are caused by a worn pinion to rack. - this is, imo, not the case here.
A Power assist valve issue - on a perfectly normal rack - could well cause loss of, and progressive reduction in assist in as single direction only.
Tony is correct in suggesting removing the PS belt for a small test.
If EQUALLY heavy in both directions then the issue is probably the PSU. It will certainly be the Steering RACK if this is the case - not the pump unit.
Hope that helps ?
Joe.
thks and kept a note of what tony has said and won't just pin the fault with the drive shafts
will make sure they test it out fully and know they wouldn't rip me off
imagine it will be a few weeks until i can get the car in the garage , but will of course keep everyone up to date of findings
do appreciate the heads up