I don’t know how stable or not TB218 trucks are stock. First thing I did was swap out the bushings for Venom barrels and double barrels… Higher rebound bushings in the front and bushings with much less rebound in the back (more dead feeling) to dampen the wobbles from the rear.
I also printed out these little stability keys out of Nylon. https://www.thingiverse.com/thing:2855766 They work great to improve stability and manuverability on my other trucks, and my TB218s are super stable above 40MPH and turn great. It’s suprising how much slop they remove just wiggling the trucks back and forth with and without them.
I also spoke about some of the other stability improvements I’ve made to my trucks here if you are interested… Like for example if your bushings have any play around the kingpin and you are using flat washers or cup washers that don’t hold your breath center, it does not help to hold your trucks center either, resulting in slop, unpredictability, and instability.