Kubota b7500 manual transmission issue

[Cruizer127]

So I have a Kubota b7500, (not sure what year) and I took the gearbox under the seat apart to replace the arm main **** pin, but I can't figure out how to get it all back together, there was this little ball that fell out when I popped it open and now I'm not sure where it goes, any ideas would be super helpful