2000 Mazda 929 mileage: 102,000. My automatic transmission is slipping in low speed usually on takeoff, it revs up to 4000 rpms before shifting, I’ve already had the transmission position sensor replaced, but that did not solve the problem, the mechanic thinks it's possible that the torque converter needs to be replaced. What do you think? Is it possible that this transmission will have to be rebuilt or is it something minor. Thanks!