The one I did years ago was much as described here with a coupler:
https://www.renntech.org/topic/43336-m967-polyvinyl-chloride-rear-main-seal-installation-tool/
I did it myself because after paying a reputable shop to do it on a 1999 along with the IMS for $Thousands, it was leaking again a year later. A great shop, but after that and many years of being around aircraft mechanics, I'd usually rather face my own mistakes than trust a random professional.
While I understand that the $512.13 tool from LNE will do it in seconds correctly every time, the economy is not there for me to buy one to do two engines. The $100 ones can probably be used incorrectly, but it seems like a step up from the old PVC method. The one I think I want is a simple 3d printed version:
https://www.ebay.com/itm/385580879017? For a $30 seal and an afternoon of labor I could make mistakes a couple times before I'd be telling myself I should have gone LN. Does that make any sense?
