..have a new SACHS flywheel here.. so I will use the new one. Car has 70 k mls on the odometer.
Rear main seal... I have a new one, but if the current one is not leaking... why change a running system. ? Will say ..the OEM Stuff is always way better than the replacement stuff. So I am a little afraid, that I install "new piece " with minor quality.
But you are right... IF there is some oil smear / leak the rear seal must be changed.
Saw a video where they pull the bearing retainer.. to change the oil seal. Looks like a good way to go..