5HP18 ball (one-way check valve) diameter needed

[shogun]

updated links
here a copy bulletin of that http://www.europeantransmission.com/....BMW/01-34.pdf
from this main link http://www.europeantransmission.com/...MWtechinfo.htm
https://www.transmissiondigest.com/november-2001-issue/
Before or after overhaul, vehicles equipped with ZF-5HP-18 may exhibit a bind-up condition in the Manual 2 position, 1st gear.
The cause may be that the plastic D-clutch one-way checkvalve assembly in the lower rear valve body (#15 in Figure 4) is broken, allowing the B clutch (reverse input clutch) to be on while the D clutch (low/reverse clutch) is on in 1st gear.
Replace the D-clutch one-way check valve assembly (See Figure 5) with a new assembly from ZF, or a new aluminum checkvalve assembly offered by Mario Aristides (phone 305-666-3544 or fax 305-666-8238).

https://aftermarket.zf.com/remotemed...fc-5hp19fl.pdf
https://www.bmwe34.net/E34main/Troub...ch%20Guide.pdf