My S4 is in the shop right now for a torque converter replacement.

I have 66k miles on it. It has been giving me the Check Engine Light and torque converter clutch stuck code since 59k miles. It isn't like the car wasn't driveable, but it won't lockup for gas mileage at higher speeds. So going down the highway with the torque converter unlocked causes it to be revving near 3000 rpms at 75-80 mph and it sucks a lot of gas.

I wish that Level 10 would sell the higher stall torque converters outright and not need to have the old one sent in or I would have put in a higher stall unit for better launches. I don't drive the car hard at all so I guess I was just one of the lucky ones that will experience the seal going bad. Hopefully this one lasts a lot longer than 59k miles.

If I ever put K04's on my car I'm going to have to get the Level 10 converter rebuild and also send them my valve body for the rebuild and modification. Apparently with those two upgrades the transmission can survive fine behind 450 hp. We'll see in a few years.