The Stovebolt Site Forums The Shop Area Engine Shop Rear Crankshaft Seal

I'm getting ready to change the oil in my 216 before firing it back up after refurbishing (no internal work done) Like many of these engines, my rear crank seal leaks, not bad but it does leak. Are there any products (oils, additives, etc) that might help this? I don't want to fix the seal right now because when I bought the truck, I started tearing it apart immediately. I want to get it back together and drive it a bit to see if anything else in that area needs attention.

Lucas make a pretty good oil stabilizer that will probably help. I'll usually run a thicker oil in the summer, too.

Try this- rear main seal replace . It will probably take you all of an hour to fix it right.

Oly Like those instructions I'm glad you posted them I thought I was going to have to drop transmission to get enough crankshaft play

I've replaced a bunch of the old rope-type seals over the years, and there are a few tricks that website didn't cover! Soak the new seal in lightweight motor oil before trying to install it, and you're more likely to succeed on the first try. There is a seal installation kit that's available at most professional-grade parts stores that makes the job a lot easier. It usually includes a pull rod with a threaded end that is used to pull the old seal after dropping the crankshaft a little by loosening the main bearing caps. Once the old seal is out, thread a piece of soft wire into the seal slot, and tie it to a piece of soft cloth. Soak the rag with carb cleaner, or some other good solvent, and give the slot a thorough cleanout to remove any bits of the old seal that might have been left in the block. Most seal installation kits include a "Chinese Handcuff" device to aid in pulling the new seal into place. Just don't stick the new rope seal too far into this device, or you won't be able to remove it once the seal is pulled into place.

Next- - - -roll the oil-soaked new seal on a clean, smooth surface like a piece of glass, to elongate it a little. Pull it into place with the seal installer, and remove the installer. Use a wooden dowel rod, or a hammer handle, etc., to pack the seal tightly into the groove, and tighten the main bearing caps (other than the rear) to snug the upper seal into the groove. Use a razor blade or a utility knife with a SHARP blade to trim the seal almost flush with the block. Be careful not to scar the seal surface on the crankshaft! Install the lower seal in the main cap the same way, soaking it in oil, and rolling it into the groove with a dowel or a hammer handle to completely fill the groove, and cutting off the excess nearly flush with the cap. Don't overdo leaving part of the seal sticking up on top or bottom, or the seal will spread out and prevent the main cap from tightening properly. Torque all the main caps to specifications, and reinstall the oil pan with a new gasket. Be sure the pan end seals fit properly and overlap the side gaskets correctly, ot you'll trade the seal leak for a leaky pan gasket! I like to glue the side gaskets to the block with 3-M trim cement, the yellow "Gorilla Snot" that sticks it tightly to the engine. Put a small amount of RTV rubber sealer in the area where the end seals and the side gaskets meet, but don't overdo it. I've seen excess RTV get into the oil pump, and block the relief valve partly open! Good luck!
Jerry

Good information Hotrod Lincoln. Thanks. I hope someone will see that this is added to the tech tips.