Changing the suspension arms means the weak spot is then the spigots/screw-mounts for the arms, some problems are introduced during mods - such as overtightening a screw, which leads to cracked mount = imminent failure.

I bought a few secondhand tanks a week ago, and it suprises me how much he had battle-damage his had (now repaired) compared to my tanks, and I've had mine longer!! (guess I just look after my stuff, respect it and it will last )