I have a kyosho mp9e evo v2 and the other day the center diff started slipping and getting no power. I opened it up to reveal some very dirty fluid with the consistency of tar. I looked for a while and settled on trying the silicone ear plug center diff fix since I mainly bash. I have yet to get it to work i only have rwd and the sun gear just wont make contact with the others. Am I doin something wrong or should I just stick to oil. Any suggestions on what oil to use? I have no idea what weight is in the front center and rear.