I have had (what I think) are chronic issues with the rear main seal on my 500 stroker. Crank is a 440soruce 400>>500ci 4.15 stroke. I have had leaks with:

- stock retainer + regular rubber seal (2 different seals)
- 440 source billet retainer + viton seal (currently installed)

I am going to try and pull the oil pan in the coming weeks and inspect the seal to confirm. In the meantime, I feel like I should go ahead an get a new seal so I am ready if it does appear to be leaky when I pull the pan.

I see 440source has two seals (above the standard rubber) - the Viton seal and the old school rope seal: here

With my history in mind, should I do another go round with the Viton seal or try the rope seal? Before anybody asks, I did ensure the two seal halves were not lined up with the retainer/block joint and used a dab of RTV around each joint of the retainer/block.

Also, I purchased the windage tray that has the silicone seals integrated from Summit. Any experience with these? Seems like such a great alternative to the PITA gasket sandwich.

Any help is greatly appreciated! Thanks!

Have you verified that it is the main seal leaking and not the side seals leaking? If not do that first before trying again. If it is the main seal it will leak out onto the crankshaft flange and the oil will be slung out onto the flex plate and outwards from their If it is leaking out of the side seals it won't be on the crank flange
I haven't had a rear seal leak in a lot of years, 100s of BB built.
Let us know what you find out, maybe I can help you stop this

Hey cab, Did you put any oil in them ??? LMAO Sorry couldn't resist

Agree here. It’s not the type of seal or the caps fault, it’s how you install it.

that likely won't seal properly on a stock style pan rail due to the stiffening beads. Mr gasket says its made for a flat pan rail. See their note below.


Pics below show the problem

Yep, leaked with our dimpled pan.
I was sure excited about the idea though.....

What brand pan is that??
I like the baffling.

Joe

My pan is a Moroso and it has flat rails (no beads). I am assuming you would use no RTV on this tray save for a dab at any joints?



I am open to any tips on installation. Which orientation to install, where to use RTV, etc.

Milodon

I had (thought I did) same issue on my 1st Gen 392 Hemi. Replaced rear main seal several times. Still had "the" leak. Finally found out rear of valve cover leaking, not the rear main seal. Just something else to check out.

there is also the rear cam soft plug. that is somewhat uncommon, but it bit me one time long ago. i can't remember what engine it was though.

Please confirm this is the correct orientation for the crank seal and side seals.

Looks good to me.
Seal the sides up after it is installed correctly and make sure the bottom seals slide all the way in to the touch the block on the bottoms of both of them before sealing the sides up
Let us know how that works out

Look leaky?

While I am having a little bit of a problem figuring out exactly what I am seeing there it kinda looks like the crank has knurling?

It was pretty much the standard for the factory to knurl the seal surface on the cranks back in the day, BUT they ran rope seals.

If that is a knurl you need a rope seal. The lip seal needs a flat surface.

Most old used cranks have the knurling worn down by the time we get to them so if the surface is smooth where the seal rides, then a lip seal is OK.

At least that has been my experience

Never heard this before. True or not?

Had a customer several years back that had changed the rear main, pan gasket and even the oil pan several times. first question I asked was who put the oil galley plugs in. He said he hid and SWORE the were sealed and tight. OK.
We proceeded to do the rear main and pan gasket 1 more time. Still leaking. After thoroughly brake cleaning the back of the motor and letting it dry, we started it and let it run for several minutes. We shout it off and using mechanical fingers with a small paper tower wadded up, I carefully snuck it up in bellhousing avoiding the bottom and rear main area.
When I removed we had oil. I said oil does not run uphill. We pulled the trans and flywheel while he watched. The RR galley plug was only finger tight with no sealant.
he left a pan gasket here so i had a sign maker buddy mount the gasket with "THINK OUTSIDE THE PAN JON" LOL

Poor guy he said his driveway looked like the EXXON Vladez had been docked there LMAO

My cam plug looks dry. Can anyone confirm that the crank knurling requires a rope seal? It would seem 440source would note that on thoer website since they sell so many cranks..

I don't believe that's true. All the BB cranks that I've seen have the knurling. The knurling helps keep the oil from getting past the seal as long as the knurling was done properly and not backwards, where it would direct the oil past the seal.

There are 2 ways to knurl a sealing surface. Crosshatch and diagonal. Some new cranks use a diagonal pattern that is supposed to draw the oil away from the seal while it is rotating. This is not a problem with PTFE seals that actually seal fine in a dry or low lubricant environment. This is why many new engine have their seals installed dry.

The crosshatch pattern mopar used back in the old days would draw oil to and away at the same time. Worked good for the rope seal and it's wide surface area, but lip seals slide across the grooves letting the oil pass by underneath.

Your crank looks like a diagonal pattern.

I went a round on a GM that had the seal replaced and it still leaked before I got a hold of it. I read more than any human should about seals when it came my way and the one thing I learned is there is a lot of debate on sealing technology. That's when I discovered some seals are installed dry.

Any idea on who made the crank? What are their opinions? Is the current seal a PTFE or traditional seal?

I am open to differing opinions. I hate rear main leaks and love to hear what works for others.

To clear some technical confusion, the purpose of any rubber seal having helix grooves is to physically throw the oil back in towards the engine... if the seal is installed reverse (with the grooves facing the transmission, it will physically pump oil out of the engine.

It make no difference if the crankshaft has knurls or not... they are there to keep a small amount of oil on the shaft where the seal makes contact.

Rope seals were simple, back in the day, to install and low cost to manufacture... as well as the casting grooves for the seals were not dimensionally held at tight tolerances... where as rubber seals more commonly need a tight fit into their retaining grooves.

I'm a former gasket engineer from a major company... these are common questions being asked.