Replaced RMS. Now oil leak really bad.

[DirtyComanche]

22 minutes ago, PocketsEmptied said:

 

Isn't Fel-Pro a double lip?

 

The above didn't work this time either :/

Fel-pro is a double lip from the P/N on Rockauto.

[howeitsdone]

2 minutes ago, DirtyComanche said:

Fel-pro is a double lip from the P/N on Rockauto.

 

That's what I have. BS40612.

 

Just not working right and I've got a feeling those gashes are my culprit.

[DirtyComanche]

Before you give up, make sure your CCV system is venting right.

 

I toasted a 400 SBC because of that.  Couldn't get the rear main to seal, tried multiple times, finally one day I ran it out of oil.  Turns out it was a breather issue pressurizing the crank case.

 

But yeah, those gashes aren't going to play will with a double lip seal, assuming they're as bad as they look.

[howeitsdone]

6 hours ago, DirtyComanche said:

make sure your CCV system is venting right.

 

I added an auxiliary filter to keep the oil out of the intake. Could this be the problem? Maybe the filter I put on is restricting too much?

 

[Tex06]

On 5/9/2022 at 11:16 PM, PocketsEmptied said:

 

I also have that leak too. But this particular leak comes straight from under the RMS. I laid under the truck while it was running to verify.

If you have that leak I would fix before chasing the RMS. Mine also leaked down exactly below the RMS when I laid under the truck, not off the starter itself. I'll see if I have any of the pictures I took...

 

[howeitsdone]

1 hour ago, Tex06 said:

If you have that leak I would fix before chasing the RMS. Mine also leaked down exactly below the RMS when I laid under the truck, not off the starter itself. I'll see if I have any of the pictures I took...

 

 

Went ahead and fixed this week. Had the parts, just had to do it.

 

[AZJeff]

On 5/13/2022 at 3:16 PM, Pete M said:

maybe time to try the double lip? 

 

but as I said, it took several tries to get mine to stop dripping.  2 different seals, and many attempts at getting the goo everywhere it needed to be. 

I am not sure, Pete.  That crank has a number of defects in the sealing area, and the photo only shows 1/2 of the total circumference.  The other side might be worse!

 

Also, those striations (diagonal lines) on the sealing surface are something I have only seen on shafts that typically also have an oil slinger.   It’s not something I have ever seen on a crankshaft before.

 

How did the striations get there?  Is a special seal employed with that sort of surface?  (I am trying to remember if any of the cranks that used those “rope type” seals had those striations…..)🤔

[DirtyComanche]

16 hours ago, PocketsEmptied said:

 

I added an auxiliary filter to keep the oil out of the intake. Could this be the problem? Maybe the filter I put on is restricting too much?

 

I'd try putting it back to stock if nothing else.  There is a partial vacuum on it the way it was designed and routed into the intake.  That filter *should* be okay like that but when you mod anything and there is another unexpected result, it is always good to back up a few steps and see if the modifications are causing the new issue.

[DirtyComanche]

1 minute ago, AZJeff said:

I am not sure, Pete.  That crank has a number of defects in the sealing area, and the photo only shows 1/2 of the total circumference.  The other side might be worse!

 

Also, those striations (diagonal lines) on the sealing surface are something I have only seen on shafts that typically also have an oil slinger.   It’s not something I have ever seen on a crankshaft before.

 

How did the striations get there?  Is a special seal employed with that sort of surface?  (I am trying to remember if any of the cranks that used those “rope type” seals had those striations…..)🤔

Rope seals use those, they basically pump the oil back out of the seal.  As to it being right in this application I just assumed it is, as I don't recall if any of my 4.0 cranks looked like that or not, and I'm not aware of any way to add those short of a machining process with the crank out of the engine.

[AZJeff]

4 minutes ago, DirtyComanche said:

Rope seals use those, they basically pump the oil back out of the seal.  As to it being right in this application I just assumed it is, as I don't recall if any of my 4.0 cranks looked like that or not, and I'm not aware of any way to add those short of a machining process with the crank out of the engine.

So did AMC ever use a rope seal on their six cylinder family from which the 4.0 is derived?  (Is this crank possibly out of one of those older engines?)

[DirtyComanche]

2 minutes ago, AZJeff said:

So did AMC ever use a rope seal on their six cylinder family from which the 4.0 is derived?  (Is this crank possibly out of one of those older engines?)

Maybe, but not likely.  Rope seals were largely obsolete by the 1960s.  I don't think there would be any AMC I6s that would use one and have any sort of interchangeable crank with a 4.0 based on that.

[howeitsdone]

The seal I removed was AMC branded. Obviously these gouges came from something though; striations aside. If it was changed at some point then I just don't know what they were thinking. It's not like the gashes are on opposite sides where the seal would sit

 

23 minutes ago, AZJeff said:

The other side might be worse!

 

I turned the crank around and the other side is fine. There is a light horizontal marking that sits in center of the seal.

[AZJeff]

Aside from the nicks in the crank, those striations are going to make the seals job just about impossible using an OEM rubber lip seal.

 

 

I really don’t understand why they are present if the engine used the normal two-piece rubber Kip-type seal😵‍💫

[Big_Mark]

Peanut gallery idea, I've used JB Weld to fix scratches in cylinder walls before with great success, perhaps you could remove crank, clean the scratches, jb weld the defects, sand off excess JB weld then try again?

With that said, it's a lot of work to remove the crank, and if the crank is out of the engine, why not just take the crank to a machine shop to see if they can do something about it?

 

Also I've worked on 2 different 258 engines, 84, and 85 both had rubber RMS, no ropes.

 

Good luck brother, sorry your fix turned into a new problem, that is the absolute worst feeling: "I broke my Jeep fixing it" 

 

[Tex06]

On 5/15/2022 at 2:06 PM, Big_Mark said:

Peanut gallery idea, I've used JB Weld to fix scratches in cylinder walls before with great success, perhaps you could remove crank, clean the scratches, jb weld the defects, sand off excess JB weld then try again?

With that said, it's a lot of work to remove the crank, and if the crank is out of the engine, why not just take the crank to a machine shop to see if they can do something about it?

 

Also I've worked on 2 different 258 engines, 84, and 85 both had rubber RMS, no ropes.

 

Good luck brother, sorry your fix turned into a new problem, that is the absolute worst feeling: "I broke my Jeep fixing it" 

 

I was going to suggest this but without removing the crank. 

 

It's not going to make the leak any worse.