Need Help with B1 Piston W124 400E transmission 722.354

[werminghausen]

I am preparing the donor transmission for install tomorrow.

I built a tool to remove the B1 piston cap and removed B1 piston assembly.
Was easy.

Problem now is that I took the cap and B1 piston entirely apart except for the Teflon ring.

Cap and Piston are connected with a 10mm shaft and are 'secured' with a teethed washer (see pictures). That washer sits in the piston secured by a ring clip.


When I pulled the 10mm shaft out of the piston there was great resistance from the teeth of that washer but I could disconnect in the end.

But now I cannot get the 2 parts together again easily because the teeths of that washer (teeths are curved slightly towards the shaft-outward- and do not allow the shaft to enter).
But if I could get the shaft in with force how do I adjust the distance between the piston and cap?

I am not certain what to do but I need to do something (running out of time).
Worst case the pressure of the piston is not enough to push the piston towards the brake band.

What is the purpose of that design? I don't quite understand... maybe to restrict the return movement of the piston when the oil pressure drops and the springs push the piston back...but only a bit and not all the way?

Who can help?

Martin