Originally Posted by kufman

Agreed, ditch the brace. The problem is also partially caused by the use of Losi's cheap plastic spacer that goes under the motor mount. I ditched that as well (had to grind the chassis for spur clearance) and I have never had a problem with the motor mount coming loose from the chassis. I don't even use locktite anymore. An alternative would be to build a spacer out of something that isn't so soft like aluminum or carbon. Without the spacer, a 42mm motor sits very close to the chassis. With the 2.0 and 3.0 chassis, the flex may cause the motor to hit the chassis and you will have the same problem as the brace caused.