u/AccurateFilm7024

I just bought this rubber 2weeks ago, why the rubber became like this? Anyone know the reason?

Hi everyone, I was wondering if anyone else has experienced the gearbox cover cracking like this? I’m pretty sure it wasn’t cracked when I first assembled it, but it started cracking after I ran about 7 to 8 battery packs. Did I overtighten the screws? Any advice on how to fix or prevent this would be greatly appreciated!