my st170 has developed a clunk, and what feels like, some resistance when turning the steering wheel from central, to left.
I've recently changed the wheels from stock, to a aftermarket set which are the same size, but a slightly different offset. The problem seems to have appeared since fitting the wheels. Perhaps this has just highlighted a issue.
Ive done plenty off googling regarding the above problem, and all the information points to the rack being worn. However i thought id ask on here first.
One thing I have noticed is the power steering fluid is black, im going to flush it tomorrow, although im not hopeful it will cure the problem.

If it turns out to be the rack at fault, how safe is the vehicle to drive. Is it likely to completely fail?
Thanks