I have two of these that my son and I race. I put Associated ball cups all around on his and it seems to be holding up. I also locktite-ed the servo saver knurled nut to keep it from going loose. Shimming the axles through the wheel bearings on either or both sides help remove some slop there. I put aluminum carriers in the rear and castor block and knuckles on the front of the boy's car and added aluminum locking drive hexes. The wheels spin freely without excess wobble. Untrue wheels are another potential culprit. I'm going to take mine completely apart and rebuild it with locktite on any screw going into aluminum and new ball cups as I got frustrated and got a different chassis to race with. I will race this again in VTA.
I setup my chassis to use the 5000mAh Venom 30C packs by removing a bit of material on the swinging latch on each side so that the plugs are not blocked. I'll post up some pictures of my mods soon. I have my work cut out for me.
Building/working on these is half of the fun for me.