This is part 2 of a previous post where I was trying to find where an oil leak was on the front of my engine. It's a 2011, 3500 4x4 dually w/ 6.7, and all the lame CA smog crap on it. I just changed the CS seal and sealed the cover. The seal was fine (just preventive while apart).
Well, Found the leak! It sucks. It's the gasket between the block face & timing gear case.

There are few things bothering me about this.

1. Why? Now I have noticed that on this gasket, the bolts are spaced fairly evenly around the perimeter. However, in the location where it failed, it goes more than twice the distance with no bolts. Don't know why Cummins did this, but it leaves a long skinny segment vulnerable to getting blown out. Or in my case (oddly) sucked in. So my concern is, "why did it get sucked inward? I don't want to fix it, only to have some other problem causing to do it again.
I've done the tea kettle test & it sits dead calm. I've held Saran wrap over the oil car hole and it's dead calm. Took off the CCV filter, did the Saran test over both the valve cover hole & CC tube hole at the same time, and nothing was huffing or puffing. No pos. or neg. pressure. Even reving up and down. Could there be something that would cause it to have enough vacuum in the case to suck the gasket inward?

2. To replace this (correctly) it involves tearing half the damn truck apart. Worst of all, I have to screw with the guts of the engine (camshaft, rockers, tappets, the cover & CS seal I just did, etc.), that is working perfectly. Last thing I want to do is screw with that. Can it be done ANY other way? Is there enough slack behind the cam gear to move the plate forward (with the camshaft in), and clean & nurse a new gasket into place? Even if it takes hours just to do that (working in a 1/4" slot), it still beats DAYS of pissing around the other way. (I'm guessing the answer's No)

3. Given that the opened area is up at the top and doesn't have a lot of pressure and isn't bathed in oil, has anyone ever tried sealing something like this from the outside. The equivalent of "caulking" that entire seam across the top? Obviously using a material that is oil proof. And after cleaning the bajeebers out of that entire area & seam. (I know this is a Band-aid. But band-aids sometimes work for a loooooonnng time.)

Any thoughts?
Thanks all !

 

Wow. That sucks.

You had a few of the same ideas I did though.... Changing that gasket without disassembling the whole friggin motor..... I think the problem there might be getting in between the block, and gear case, to clean off the old gasket..... Wonder if you could pull the front cover, clean the leak area REALLY well, and seal it up with some RTV from the INSIDE, and also lay a bead on the outside??

Edit: Looking at cams for your engine, it appears that the cam gear does indeed just bolt on???

 

Regarding the cam gear; so far every vid. I've watched shows 1 piece. I could be wrong, but I've been looking. (That glimmer of hope thing.)
You've got a good point about going inside & out. After looking at the casting, it turns out that that section is opened to the bottom side. If you look at this pic I screen captured, you'll see that to the right there is a back plate covering the area. I was afraid it went in the area where the leak is. But it doesn't.



As much as I hate to pull off the cover that I so beautifully just sealed up. I think I will. If nothing else. I can see where the gasket has gotten pushed to g possibly loosen some bolts, add goop, & push back up into place. Then seal the crap out of it.

 

Ok, did a bit more research. The cam gear is separate from the camshaft from 1989-2018...... Looking at your pic there, I bet those bolt holes around the cam hole are for the camshaft retaining plate. So, don't have to pull the cam, to pull the cover. Still, there is a LOT of other stuff there that would need to come out of the way.....

 

Sorry for the long delay. Regarding the cam shaft, I'm attaching a pic of mine. Definitely, one piece. That said, I'm not taking this puppy apart.


Today I was able to warm up the cold stiff gasket and get it mostly back up into the slot. Then made a fillet along the underside in that area, and a large fillet along the entire length of the topside with the oil proof Permatex. If the Permatex is half as tough as it was when I put it on the timing cover, it should outlast the truck. That stuff took forever to scrape, and wire brush with acetone, to get off. It is really tough stuff. I was impressed.


Gave it dry time today. Putting back together tomorrow. Then 24-48hrs to get solid on the timing cover and will test it.

 

Cam gear is keyed, and just presses on.

 

The latest.
It's back together and did a short run with no leaks. Time will tell. Need to drive more than a couple minutes. However, thought I'd share something I did while waiting for the timing cover gasket seal to cure.
So far I've been really impressed with the design of this engine, from the standpoint of working on it. With the exception of that lame Timing gear case that requires you to take half the engine apart just to take of the casting. There are about 5 ways I can think of that it could have been designed to not require that. That said, one of the things I really like is the way you can just spin off the fan and pull it out to get easy access to the front of the engine. Almost!
To pull it out, you have to deal with the fan shroud. But to pull it out, you need to move the air box. Then wiggle an waggle the fan shroud out, dodging the various hoses &trying not to touch the fins on the radiator. All while lifting the shroud & fan & holding the elect. connector from the fan from snagging on everything. So I decided to do this.
I split the fan shroud on the sides. Made pins & tubes to go in each half. Then epoxied then all in to the shroud. I love it! Now, the bottom stays on all the time. I take out 1 plug & 3 bolts and take the top half off. Spin off the fan and lift it out. IT'S SO EASY. I'm sure the experienced hard-cores that work on these all the time will think I'm crazy, but... to late. That's old news.



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It should have been two-piece from the factory.

That is a great mod.