I get this annoying knocking sound that seem to be coming from having a loose steering rack or something I can't trace yet. I searched here and the closest I found was by bakeoff and I quote:

"it could also be a loose steering rack. There is a 14mm nut on the bottom of the rack. It puts tension on the driver's side end of the main shaft in the rack.
Jack it up, have someone crank the steering wheel until it locks, and then hold it tightly against the lock. With it held firmly, go to both sides and try shaking the wheels side to side and top to bottom. If you have any side to side wiggle, it is steering related. Any top to bottom is ball joint related. Having the steering wheel locked and firm up against the lock is crucial. It took having two people helping for me to finally figure out the steering rack issue on my hatch."

Where is this 14 mm nut on the bottom of the rack in the attached picture? This picture also came from HAN. Good stuff!

Also, from 1 to 5 scale, how hard is it to replace the steering rack bushings with Poly rubber?

Thanks in advance.