After several days of thought I now firmly believe that there was no bearing at all and I simply did not noticed it before my first run. They must have poor quality control in China because i just noticed that one of my rear shock body was in fact a front one. Anyways, yesterday I cleaned my gears with varsol, dried with compressed air and re-lubed everything. I also bought Vertigo's sealed bearings kit for the gearbox and HPI baja 6mm front shock shafts. I rode for one hour tonight and everything was fine except for the two beadlocks ring that broke.