Kubota B7001 gearbox shim trouble

[Dieselmonkey 6410]

Hi !, this is my very 1st post !, I’m in Australia and have taken apart the gearbox to put new bearings in . The gears seem all ok , but there’s one shim which is 46mm od, is 1.5mm thick and 30mm Id
I think it must go in next to or between bearings in end of case possibly . Maybe on the bottom pto shaft , but diagram and parts doesn’t state the size of shims , and makes it difficult to know . Please if soneone can help me , thanks