John,
No verbals here, there is something amiss that needs investigating thoroughly. There is no sense in putting that shaft back into place in this condition.
Christof, it appears that the bolt is not screwing fully home. The washer under the bolt head should fit flat to the spot face on the casting, which it is clearly not doing.
Is it because the bolt is not fully tightened and it is just finger tight?
The end of the bolt shaft should probably screw through the shaft and into the rear hole of the casting, which would then fully lock the casting onto the shaft.
Do you have a photo of the rear of the assembly?
If not, and you cannot get the bolt all of the way through, then maybe the casting holes are miss-aligned.
I notice that the casting sports the correct casting number though.
Apologies if my previous post appeared rude, no malice intended here, we are all only trying to help
Regards
David