The Stovebolt Site Forums The Shop Area Engine Shop rear main rope seal installation

I've got a '55 235 that I'm reassembling. I got the crank in, mains plastigaged and shimmed, neoprene lip rear main seal in and everything torqued down. As I was putting it together I noticed that the OD of the crank flange was lightly pitted. This is the surface that the seal lip rides on. I got nervous about the possibility of it leaking so now I've got it pulled back apart and am going to use the rope seal instead. I think it had a rope seal in it before and it was dry as a bone. What's the proper way to install it? Does it get installed dry or do you soak it in oil first (as I've seen online a couple of places)? Do the ends get cut flush both on the block and the cap or are they cut to stick out slightly on one or the other? Do the mating ends get some RTV on them or not? I welcome all experienced builders' advice. (No speculation please, I can guess with the best of 'em and I don't want to bolt this motor together with guesses.) Thanks in advance, Dale

This is covered extensively -

Putting this:
+rope +seal +installation

in the search field will return you a few weeks worth of reading!

https://www.stovebolt.com/ubbthreads/ubbthreads.php?ubb=showflat&Number=20274&Searchpage=1&Main=3295&Words=%2Brope+%2Bseal+%2Binstallation&Search=true#Post20274

Hotrod Lincoln (Jerry) describes it well in the above post.

Good luck!
Mark

#20274 - 05-16-2004 12:00 PM Re: Rear Crankshaft Seal
Hotrod Lincoln
Master Gabster Registered: 02-23-2004
Posts: 7774
Loc: Dellrose, TN

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
_________________________
Silly Viking! Pillage, then burn!

Only thing I could add is to make sure its a seal from Best Gasket

http://bestgasket.com/engine_catalog_years.asp?YearsCID=1950-52,%20235.......[534]

This is by far the best seal on the market. Follow the direction included with the seal exactly and you will not have any problems. Don't deviate from the directions!

I used a lot of feet of this seal material packing valves, piston rods, and pumps on a Stanley Steamer, probably 30 feet of varies sizes, and not one has leaked yet with 500 psi of steam!

Joe

Thanks for the help guys!

Dale