F134 Rear Main Seal Replacement?

Is it practical/reasonable to do an in frame replacement of a neoprene rear main seal on a F134 engine? Any hints? Am I crazy? I really don't want to pull the engine if I can avoid it.

 

I've done neoprene RMS's in frame (not on a 134) without loosening any of the mains. They rolled out without too much muss or fuss. Tapped the top one loose with a pin punch on the steel insert, then pushed/pulled it around (see how easy it sounds).
Biggest issue for me was the installation. Be careful to fully compress the seal against the crank while installing or you run the risk of pealing off the back of the seal off on the sharp edge of the block.

Oh and be sure the seal lip is pointing in the right direction.

If the old seal is a rope one, you may have to punch out the little stake on the bottom cap (if it has one).

 

It's not that difficult, just a hassle upside down with oil dripping everywhere.
Pay attention to the runner plugs and don't cut off flush.

It just takes patience and beer.
Some folks have more of one than the other.

 

Mission accomplished! I replaced the rear main seal inframe today. Honestly the job went well, the worst part was cleaning the 60 years with of oily grit off the pan and other parts. I pressed the clutch in with a 2x4, loosen the rear main cap and didn't need to touch the torque on the mid or front cap. The old seal slipped right out without issue. I lubed up the new seal and turned the crank by hand and slid it around the top without issue.

Now in all honesty I did cheat a little as I have a four post lift in my garage so I was not on the ground doing the job. I would say if I had to be laying on my back getting up and down 12 times it would have made the job three times harder.

Thanks for the insight, tips, and encouragement.

Mark