My own view having just reset the rack pre-load is that if your car has a Quaife rack (2007 on), is over six years old or shows any signs of too lively steering and/or any play, then take the adjuster apart. It's very easy to do with correct tools once the lock tabs of washer under 38mm locknut have been bent down.
My plastic plunger/rack follower hadn't seized although was a very snug fit so maybe not far off, which is why I took at tad off with oiled wet and dry. I suspect it's expansion is more time than mileage related though.
On re-assembly I adjusted after tightening down then backing off the recommended ¼ turn. Afterwards I measured the before/after difference of threaded adjuster above locknut. It sat just 0.05mm lower equating to little more than ¼ turn of slack taken up.
Having driven the car yesterday over far more than a quick test drive I can confirm this small adjustment has made a noticeable difference. In essence the wheel feels calmer over bumps with the skittishness that had built up over time having
gone.
