so far for an aluminum servo hor the only one that i could find that use 4/40 is the losi. i have no idea if this will work yet or not but i might buy one and try it out and see. all the rest have a 3mill thread so unless there a conversion i dont know about to get the ball to work.. the losi might be best. im a little mad the ft team did not come with the 12mm hexes bummed out there so there like 3 or 5 more things to get now. do those avid hexes get a ride of all those shim for the rear tire or do you still need them?