Need a steering colomn guru

[virtualfern]

My chim started off with quite heavy steering beyond say 20 degrees. It then eased up for about 2 weeks and felt like driving a different car. Suddenly this morning I was literally wrestling to get the car to turn into bends (nearly dumped it into a mondeo on the opposite carriage way). Any ideas?

Is the steering colomn about to implode?
air pocket with the PAS fluuid?
TADTS?

HELP!!

Thanks all

[bilton_d]

Sounds very similar to the problems i was having felt like there aws no power steering turned out to be the upper UJ on the steering, cost about £100 including parts but made the steering so much lighter afterwards.