Transmission trouble

Hello, If this is a dual clutch gearbox (DSG), you will be looking at an issue with the electronic control system within the transmission. If this is an automatic without the dual clutch gearbox, you are likely looking at slippage, but it could be anything from a cracked valve body, one of a few bad sensors, or a weak solenoid that cannot direct the flow of transmission fluid to complete the shift. As for as the transmission filter kit, there are two schools of thought. One says that the particles in the transmission fluid from the breakdown of the clutches allows the remainder of the clutch packs to make friction. The other school of thought (the correct one) says that particles in your transmission fluid are harmful to friction, clogs the filter, and can lead to debilitating accumulation of fine particulate matter inside the transmission. If changing the fluid and filter cause a loss of traction for the clutch packs, the damage is already done.