Found the problem. I already mentioned that my old code was similiar to the cxf 2.4 code. I kinda realized that with adding the AuthorizationType in my code I made HTTPConduit call SpnegoAuthSupplier in the send process. So my kerberos ticket was overwritten by the SpnegoAuthSupplier. So basically there had to be some error in the SpnegoAuthSupplier.
So i kinda compared my code with the SpnegoAuthSupplier and realized that I used the SPNEGO OID and cxf 2.4 used KERBEROS OID. I changed the SpnegoAuthSupplier and buildet the transport project. Updated my workbench and it worked. created a ticket with the working source code attached https://issues.apache.org/jira/browse/CXF-3496
