I drift a pro 2 which comes with ball diffs. i keep having trouble. i know what i am doing but when i build the diff there are only two things it does. either i lock it all the way down so it doesn't slip and then the car loops out and only spins donuts. or i either get the car on the ground only to hear the noise of the diff slipping and my cars acceleration to be slow until the diff grabs. i am no newbie to this hobby or building diffs. i think that the brushless has begun to take its toll on my diffs. This is a brand new diff with new everything in it ( balls,rings,thrust rings,thrust balls,outdrives,and pulley) and also a new belt. i have had the diff out of the car at least twenty times in the past two weeks. i think i could do it in my sleep and this is definitely not something i am proud of. everytime i try to grese it with some other grease or not so much grease or more grease. i think i have done everything. does anyone have any idea as to what is wrong. anything will help at this point. my only idea thus far is to burn the car!! just kidding i have decided that until i can figure out what to do that i will run the bevel gear diff that comes with the sport 2. it is a quick fix for 15 bucks and as you know a gear diff wont let the pulley slip without the wheels turning. hell if none has any other ideas maybe the gear diff will be in there forever it wont bother me as long as i am still shreddin rubber. actually since i have just gotten into electric cars i still would am used to tuning a gear diff with grease it is just not as easy as a ball diff.