I'm a little suprised motor failed that quick. I've killed a few of the stock motors. But took 30-40 hard runs to do so. The Dromida brushless system works fine. Avoid the aluminum spur gear. Ground up 3 of them. Went back to stock plastic.
I use a HiTech servo in one of mine. Can't remember which one, but made a big improvement. Did steering break from a impact? We run the Dromida vehicles at hobby store for fun. The short course/desert truck do really good. The couple guys that tried running the Monster truck kept having breaks. Lack of front bumper really seems to make the difference.