2013 Suspension Knock - Help needed

Reading your comments, I must admit, it really disheartened me to hear that the issue might actually be the steering rack. This is one of the most expensive and complex repairs among the possibilities I had considered. On the UK Toyota forum where I posted, the consensus seemed to lean in a different direction—they suggested that steering rack failures are rare and advised me to replace the inner tie rods first. This recommendation also aligned with feedback from my MOT inspector over the last few inspections, who specifically pointed to the inner tie rods.

With that in mind, I had already ordered the inner tie rods and was planning to fit them myself, as it's not too challenging a job. However, after hearing about the potential for steering rack issues, I feel quite deflated. It's an expensive and technically demanding job, and it really wasn’t something I was prepared for.

If you don't mind me asking, where did you get your replacement rack? Was it an original Toyota part or sourced elsewhere? Also, did you fit it yourself or have it done by a professional? I’ve been looking at options on Amayama, but they’ve been out of stock for over a year.

I appreciate any advice you can offer, especially on sourcing the rack or tips for tackling this type of repair. Thanks in advance for your help!