Originally Posted by JakeC351

hey guys just wondering if you have any ideas what can be wrong with my little brothers ft b4.1 i rubuilt the whole diff put a new idler gear in, a new top shaft, and a new main diff gear, brand new ceramic bearings and a new motor and esc new spur and pinion and it is still making a really weird grinding noise when i hold the thorottle on for a little while and when i let the thorottle off. Do you have any ideas what this can be.