Zetor 3320 PTO wont shift into ground

I recently acquired a Zetor 3320 that had been set up out in the weather and not ran for several years. I have it running now and everything is working except for the PTO will not shift into the Ground position. The PTO will not stop turning unless the Clutch brake is applied. I have pulled the PTO shaft and replaced the bearing snap ring and a new seal. No other damage could be seen in the shifting coupler or the PTO shaft splines. I have the operating manuals and shop repair manual but they are confusing.
I would appreciate any ideas that anyone has to remedy this problem. Thanks

Also|
There are two spacers on the PTO shaft and a bearing and a circlip. What order should the spacers and bearing be before installing the circlip.

Hi
Often the pin that holds the shift lever to its shaft break and coses problems like this.
Bjarne

Thanks Bjame,

I took the bottom inspection cover off of the gear box and also the pto shaft and I can't detect any slack between the shift lever and the shifting yoke for the PTO. I made an additional note in my original question about the proper placement of spacers and the bearing before installing the circlip. The previous owner may have assembled them wrong. The circlip was bent and twisted. The spacers have a flat side and a beveled side, the beveled side was against the circlip which in my opinion was what bent the circlip.

I have a parts manual if you want it, i can try to find a place to put it for download.

https://www.dropbox.com/s/dt6xt801p29yvk0/zetor_major_3320-7340_reservdelar_sec_wat.pdf

Hope this works

Thanks Fordson, I have been trying to find a parts list with exploded views and you sent me just what I needed. The drop box you used for sending the file worked great. Thank You so much.