Diff Leak in the A90 is something BMW and Toyota have not got a fix for. Once the car is tuned and the excitement level rises, allowing you to squeeze that throttle even harder more often. You are starting to work the diff harder than before. Due to the diff working harder, the diff oil heats up, expanding the oil, and with no where to go, the pressure has to be released, the oil is then forced out the seals, leaving a mess on your driveway. Please don’t ignore this as the diff only has 1 litre of oil, and you would be surprised just how fast the diff runs out of oil. The A90 Supra's do not have a diff breather fitted from factory, so in order to keep the diff lubricated and the oil in your diff and not on your driveway, we have manufactured a Diff Breather Kit especially designed to eliminate this problem.
