Crankshaft Filler Block Oil Seal & Sealant Types?


Precision Fit
Oct 23, 2009
Citrus Heights & Tahoe
First Name
Willys Model
  1. Pickup
Willys Year:
  1. 1954
Bought 54/PU in pieces w/Huricane 226

1)OK, took oil pan off to paint it. Removed oil pan gasket and crankshaft filler block. Engine was clean on exterior and everything very clean inside, looks like it's been rebuilt or at least major work...
Question is - Do I need to replace filler block and filler block guard seals? Currently they are graphite impregnated oil seals that looks new. If I need to replace is it as easy as pressing in place and cutting flush?

Any other hints to get oil pan back on w/o leaks?

2) Any recommendations on Gasket Sealant? Blue Silicone? Hylomar?

Part 1: Replacing the seals that face the crankshaft would be a judgement call. If they look good, they may seal. However, if you have it this far apart you may want to go new just to be sure. The seals get pressed in the grooves then pushed from the outside toward the center to make a tight packing. You should leave about a 1/16 inch or a little less of the ends of the seals sticking out. DO NOT CUT THEM FLUSH!! This helps compress the seals at the joints when you bolt the filler block in place.

Part 2: Do NOT use silicone!! I've used the Aviation Grade Permatex for over 40 years and it works great. Gasket sealer is only used to fill small imperfections in the sealing surfaces. the gasket seals the leaks. Silicone IS THE GASKET and should never be used with a gasket. Most people use too much silicone and the excess not only pushes out, but also pushes into the engine and sometimes actually moves the gasket making leaks instead of sealing them.

I used to run an automotive machine shop and I rebuilt a number of engines ruined by silicone sealer. The stuff that oozed into the engine would break off and end up clogging an oil passage or get in the oil pump and that was it for that motor.

Hope this helps,
Old Willy
My two cents...
In my opinion, if you have already removed that filler block you have disturbed the seal. REPLACE IT.
I personally don't have a problem with a quality silicone as long as it is used sparingly on the block so as NOT to ooooze and not on the seal itself. However, I agree with everything Old Willy stated. Listen to him. #1 - he's an engine guy. #2 - The word "OLD" is in front of his name. He's gotta be smart!! :lol: Sorry Old Willy, I couldn't resist. :D Follow his advice and you'll be much happier when all is said and done.
Now some food for thought. I have found that most of these L6-226 rebuilds are half a**ed at best. If you have not done it, you might consider pulling the head to check the valve seats. Are they the original cast or newly installed hardened seats?? Lead additive may be in order during operation. A borescope sure would be nice for this one, but hey, who owns one of those? :D
The next TWO things I would do (and remember, this is all just my opinion) is to check the valve clearences and pull the timing chain cover to inspect the chain. These timing chains don't get installed like regular (chevy, ford...) set ups. The timing marks don't match up, so put it at top dead center and count the links. Off the top of my head I believe 9 links is the number. If this wasn't done correctly you'll never get it running, so think about it.
I finally found another engine to throw in my wagon and when it gets here you can bet i'll be doing the same thing. So good luck to you and have fun with it.
Just another thought-------as long as the pan is off, get some Plastigage and pull a few rod and main caps to look at the bearings and check clearances. Also check the torque on all the main and rod cap bolts.

Also, see if the engine has been lubricated with Lubriplate or assembly lube when it was put together. If there's just oil or such you don't want to dry start the thing. I use STP as assembly lube. It sticks to the bearings and can also be used to prime the oil pump. If the engine sits for a while before you use it, the STP won't drain out during storage. Lubriplate gets hard and chunky with age so I don't like it much.

Check everything now and avoid problems later. It's time well spent.

Good Luck,
Old Willy
Thanks for all the words of advice.
Pretty consistent with what I've heard/read about silicone..

BTW...Being old is a good thing...shows you've got some juice upstairs... you can't get old if you screw up.
I am gathering that you have not seen the engine run and in fact only guess that it runs.

Being another old guy and having mucked around with a lot of old stuff, I have learned the hard way that if it ain't broke don't fix it often holds true in older components.
You took the pan off, ok and you do not want it to leak when you put it back on. Permatex has some gasket makers that work and work very well. If the pan is a leaker then you can take 3M Weatherstriping and fix it. The draw back is that don't plan on removing the pan or other object anytime in your lifetime, but it won't leak anymore.

The older stuff was put together using, cork, paper and other assorted gasket material none of which was good to begin with.

Silicone or ATV is good in fact great stuff, but it has its place and not. I have been using it since the early 60's and it excels in 2 areas. Where you have wide flat mating surfaces that a single bead placed in the center will spread out across the flat and provide a seal. Examples are differential covers, bellhousing to block etc. The other use is when you need to provide a filler material in and around a component that can co-exist with it. Were it not for the oil pickup in a oil pan it could be used there. Avoid any place that floating or sunk pieces can clog or otherwise engage with moving components.

Good rule on use: 'Less is more'.

For gasketing you often want to use a 'adhesive' based compound to offer some 'stickyness' rather just a gasket. Gaskets generally do not have any adhesive properties which is a key reason why they leak. So you if you a gasket, cork, paper put some adhesive gasket maker on both sides to prevent leaks.

If you have two good hard flat surfaces and a paper gasket then wet you gasket in motor oil. This will cause a slight swelling and provide some cushioning and compression. Such as the mating between a water hose neck and the intake manifold.

That said every application can be unique and I only provided suggestions with some examples that worked or did not work for me on tractors, ranch trucks cars etc over the years. Thank goodness todays modern components are made to better tolerances and gasketing materials are far superior to the stuff of yesteryear.

Let us know what you do and how you approach it... ;)