Rope seal trick: heres a trick to repairing a rope seal on an unrestored engine as a patch job with the engine in the car. Aside from the fact that not all engines can handle a rubber seal because of groove depth variations and poor Journal alignment.. The seal Journal must be polished to 2k grit, and that cant be done with the crank in the car. There is ALWAYS damage to the seal Journal from contamination, condensation, or just the rope seal its self over the years.. Rope seals are far more forgiving to an imperfect surface than a rubber seal.. I start by using a slide hammer to remove the cap. Then replace the rope on the cap like you normally would. They make a tool to remove the upper half (called a sneaky Pete) and those tools dont work. If you can slide a rope around the crank, even if you remove the main caps, then the rope is the wrong one for the car and is too thin and wont pack tight enough against the crank... So then you're back to doing this step, which you could've just done to begin with, provided the upper rope is still intact.. Pack the existing seal up tight on both sides with a punch, while taking care to not scratch the Journal.. Then Cut off a bunch of rope seal. Ball up the rope seal in your hand and use the punch to keep packing pieces up new seal onto each end of the old seal, as tight as you can. Then use the razor that comes in your kit to cut it off flush like you did on the main cap. Ive had about a 90 percent success rate doing this as a patch job.. Sometimes the seal Journal is just too damaged to be usuable and work, and the crank needs to come out and be polished, or the Journal needs to be welded up and machined back down if theres heavy pitting. with any type of rear main seal replacement on a 70 year old engine, explain to your customer the risks and issues you may uncover. assess the whole scenario. it may be more cost efficient to pull and reseal the whole engine.