m103 rear main seal
 

1990 300SE. The rear main seal isnt' leaking at all, but I currently have the transmission out and I'm wondering if it's worth replacing. Some say "if it ain't broke, don't fix it", but then Murphy's Law says it will start leaking a week after I put the new tranny in. Also, the manual says I need a special tool when removing the flywheel? i don't see why...