I do remember tightening the drain plug of the torque converter (14 Nm), but it could be that I'm becoming potty, so I'll check that again.

I did not check whether the seal ring fitted snugly over the torque converter shaft, unconsciously thinking that the ring was a MB part, so it must fit. The number of the seal ring comes from the EPC and that part was ordered. Unless they put the wrong seal in the bag, I don't see how that could go wrong.

I followed the FSM when I put the pump back together, so I think I did that correctly. The rubber ring #311 was indeed changed. I had to press to put the pump body in the pump housing.

I think we need another seal ring and if Autrans has that on stock, they can press it in at the same time, and they can check whether the seal ring is ok. We only have to take our torque converter and oil pump to Autrans. If I order the seal ring at the dealer, I might get the same leaking transmission. The dealer wasn't expensive for the seals.

The oil pump for the 722.315 is used on nearly all the 722.3 transmissions and a couple of 722.5 transmissions as well. I'd be interested to see which number is on your oil pump.