After transmission only trouble and a lot of white smoke change from the pot.

Hello, I hope someone can help me, otherwise I’m still going crazy. I had the automatic gearbox changed on my MV6. When the nice people in the factory sat then wanted to refill the oil, is noticed that is like a Vakum in the gearbox and the ÖL screw qasie is sucked from it. When you then fill the oil, this is sucked by the Vakum all by itself from the bottle. There is something wrong or? And suddenly the car catches like crazy white from the exhaust z u Qualms, so that means for me that the gearbox ÖL is burned somehow. The overpressure hose on top of the gearbox must then be connected wrongly or? I know this is certainly all a little by each other, but I am really very stressed by my Omega. Gearbox bought, let install, a lot of money spent and now an ÖL combustion plant in the garage. According to the workshop the overpressure claw was only pulled off from the old gearbox and on the new one on so that it can’t be wrong, but it has to be. That can’t be right.