I guess you know that the Wltoys 12428 steering mechanism has lots of 'not good' traits, like getting stuck in sand or mud, wobbling, and having a low turning angle. Most of my RC cars have bell crank steering, so I decided to upgrade this car too.
This is the first (3d print-based) version, which is not perfect and has not been tested for durability.
What you need as an extra
rod linkage (preferably with adjustable length)
two M3 bolts 13mm long from suspension (if you plan to change the stock) or order search on Aliexpress by “M3 12428-0099”, I used this - https://s.click.aliexpress.com/e/_DlK7D6b
two M 2.5 20mm bolts and two nuts. I used from there