syslog in redhat5

In RedHat 5 , classic syslog is enabled and configured to forward logs to a remote syslog server. I've noticed forwarded logs have been excluded "Date,Time" and "IP-address" of the host.

raw log example : (It is without Time , Date and IP-address)
85>sudo: em : TTY=unknown ; PWD=/home/em ; USER=root ; COMMAND=/usr/sbin/dmi

also it is not possible to change from syslog to rsyslog.
what is the solution for this issue regardless of changing to rsyslog?