Steering rack rattle

[snapdragon]

I have had a rattle on my right driver's side steering/suspension for a while now and it has progressively got worse over a couple of years from barely perceptable to now what I consider terrible. Mileage is 280,000.

I have replaced the upper arms again, ARB links again. All were pretty much perfect anyway.

A few days ago, after changing the right driver's tie rod (which appeared fine) bliss. Perfectly quiet, no more ratlle over bumps.

The steering was alightly offset, so I adjusted this the next day after work and then the next day was to test on the way to work - the rattle had returned and got worse over the course of the journey until back to normal.

It would seem this rattle was surpressed by the steering being slightly offset (I'm talking 1cm at the steering wheel rim) or perhaps the fact I cleaned and greased the rack teeth inside the bellow. Maybe the new grease gave temporary relief and has now been hot and squeezed out during steering.

I am not sure how to proceed. The rack bar (with the teeth) hidden in the tie-rod bellow was quite dryjust a film of browny/red sticky grease. I just cleaned with brake cleaner and put some ceramic brake grease on it. Maybe I should get some proper thick rack grease and lather it? Also I asume these rack teeth will not be present within the bellow on the passenger side as there is no pinion from the steering column?

Has anyone here adjusted the steering preload on the D3? Looks really difficult to reach. Is it the nut I have arrowed on the pic?
What does this actually do inside the rack?

I don't experience any steering slop or knocking sensation through the steering wheel, just I can hear a 1-2mm metal on metal type thrashing back and forth rattle over small bumps such as brown surfaces, big cats eyes, drop kerbs or drain covers. It also happens dead ahead or when turning left but not when turning right and only ever when the right driver's wheel goes over the bump.

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