The Stovebolt Site Forums The Shop Area Engine Shop BEST rubber rear seal

My 1956 block machine work in complete and time to install the rear seal. I have been reading about the BEST rubber seal and they claim it will install in 1956 thru 1962 235 blocks. Has anyone installed one in a 1956 and what are the pros and cons. I really would like to do it once without leaks.

I feel it's the best choice we have.

Before you install the oil pan, take your time to check and be sure the seal is making contact with your crankshaft--all the way around. I mention this because my 1959 235 wasn't and I had to shim the seal on the rear side by about .003. Also make certain the portion of your crankshaft which will contact that seal is smooth. If it is pitted and rough, you won't get a good seal with the rubber seal and it will wear out more quickly. That BEST seal is pretty costly. If you want to buy one of the Fel-Pro rubber seals, please contact me. I bought some when they were still available. At the end they weren't cheap, but less expensive than the BEST seal and do the same job. Also check the clearance between your rear main bearing and your crank. Regardless of which seal type you use, you don't want your crank moving around any more than it has to.
Jon

Thanks for the great info on the rubber rear seal..does the rubber seal fit in my 56 without trimming? How do you check clerance on the seal? Do you shim by cutting small slivers of shim stock and placing them in the bottom of the seal groove, cap and block? Rear bearing has 002 without seal.

.002 is good. I shimmed mine by cutting a strip of metal duct tape (the adhesive foil so common today). It gave me the .003 I needed. To check the fit I got a bright light and shined it front, back everywhere I could to see. In my case, there was one area on the left side which didn't contact nicely no matter how the crank was positioned. They say the rear seal groove from 1956 forward was concentric with the crank...and it should be, but honestly I'm not certain it is. In my case it wasn't.
Here is what the crank in the 1959 rear surface looked like:
http://i1154.photobucket.com/albums/p535/JonGoodman/ropesealcrankend.jpg
Here is a look at the rubber seal which came out of it compared to a new one:
http://i1154.photobucket.com/albums/p535/JonGoodman/rearmainendtoend.jpg

Good luck!
Jon

You want the seal to be about 1/64" higher than flush. This helps squash everything down and seal correctly. You shouldn't have to cut it, nor add anything to it from 56 to 62. The exception is if you have badly pitted crank seal area like Jon had.

Its a very simple solution, just put it in, tighten it down and forget it unless you have a very unique situation.

One thing I picked up from this site that was simple and effective. Offset the Neoprene seal. Just put it in so the ends of the seal do not line up with the block surface. Easy to do just push it a bit to one side. It ends up low on one side of the crankshaft and proud on the other side. That prevents a "seam to seam" leak. A bit of non-silicone adhesive at the very ends of the seal to stop any leak at the joint and all was good(weather strip adhesive worked for me). Install in the bearing cap so the proud side is now the low side and it fit. Easy! And the leaky mess was cured. The seal can be installed with the crankshaft in place and it works. After too many hours of wrestling with the rope seal this was so easy and clean. If I could remember the member that suggested it I would thank them every oil change.