what i did was i fully disasembeled the rear diff right then i went in my rc junk box and got a spring typical buggy truggy spring cut the spring exactly the size of rice and open up the rear diff between the small gears and put the spring cutlets about 4 or 5 into the diff rember it should b able to close the same way smoothly!listen ive tried jb weld jb quick diff locker and even spot welding.what happens is when the rear diff starts to turn the rotating mass starts to hop/wobble due to the fluid in the diff jb weld hardened where it wanted too so if one side has just a lil more than the other your diffs are off balance so when rotating at brushless speed its wobble.the spring cutletts add no weight and the same rotating mass try it !!!