jclark10

iTrader: (1)

I know this forum isn't really geared toward repair and maintenance, but I know this board is filled with really knowledgeable and smart people unlike some of the other boards where its just idiots, so I figured I would post these pictures here to see where the leak is coming from.

I've been looking all over for this leak, I was convinced it was the crank sensor but it wasn't, I was then convinced it was the oil pan gasket, and finally convinced it was the oil pressure sensor leaking down the back of the motor, but apparently not either.

I've already replaced my oil pan gasket and oil cooler lines with no effect, my 6L80 neutraled itself at a stop light and now has a noise in first and reverse so I am swapping 6L80s and just pulled my original out and see this:





My vote is 1/3 for rear main seal, 1/3 rear main cover (at the bottom), and 1/3 left over remnants from the previously leaking oil pan gasket and the oil is caught somewhere between the block and pan and all of it hasn't gotten out yet?

I am just not 100% convinced it is the rear main seal, since I feel like it would be leaking all over the place and all around the seal. Of course the seal is only going to leak when the engine is running, I just feel like there would be more of an oil stain on the rear main seal cover near the bottom where oil was coming out of the seal and running down the cover, but it still looks pretty clean? It doesn't make sense to me.

madmann26

iTrader: (7)

Get some dye and pour in the crankcase and use a UV light.

If you think it’s the rear cover, get a new one. There have been reports that the cover will leak, or seep.

Take your finger and feel on top of the cover, there is an area on top where oil will puddle if the cover is leaking.

To do it the right way, you need the rear seal alignment tool and follow the instructions carefully.

Other common areas, the oil cooler block off. Mine was leaking from here.

jclark10

iTrader: (1)

Thanks madman, and yes, I think the TSB you are talking about is: #05-06-01-034F, however, my 2011 according to the TSB should not be effected by the porosity flaws. That being said, I don't see any leaks from the top side of the cover, I believe there is an oil passage at the top part as well.

I was going to buy the whole GM cover with the seal already installed (12639250), so I guess I would have to mess with seal alignment, I think you still have to be careful putting on the already installed cover though and maybe ensure the oil pan bolts are snug first before tightening the cover bolts.

Also I put in a new oil cooler gasket, there were drips on the aluminum manifold thing, but not sure if that was drips from the leak above it or if it was actually the gasket, the gasket looked fine when I took it off, and so did the original oil pan gasket, although those gaskets are tricky to see when they are actually bad though.

Also I already put dye in, but I used the cheap advanced auto brand dye and light and glasses, which are virtually useless as basically fresh oil looks almost exactly the same as the dyed oil does. Anyway I checked it last night in complete darkness, and I do see the yellow (with a hint of green) glow as the bottom of the seal, although I can't tell if its fresh or dyed oil, either way I don't think oil should be there.

madmann26

iTrader: (7)

I bought a UV light from Amazon for like $20. Worth the money.

jclark10

iTrader: (1)

I just was taking the long 10mm oil pan bolts out and noticed, even without the light or glasses, the glow of the oil, after looking at it more I think its the rear main seal, I mean theres really nothing else that it could be since I have either checked or replaced everything else.

I hated to do it but I bought a Dorman rear main seal kit with the seal already installed into the cover and gasket. For whatever reason the printed instructions have you check the protruding clearance of the plastic oil galley seal dumbbell thing and mine is about 1.58mm protruding. The limit on the instructions is .8-1.4mm protruding. I am doing it with the end of a caliper while crawling up under the truck so there is probably some error, but im not sure if I should push it in more or what.

jclark10

iTrader: (1)

So I looked at the GM manual and things get even more confusing. So there are 2 designs on the rear main seal with included cover kits, the first design supposedly doesn't have tabs to align horizontally, the second design does. The manual says you need J41476 tool if you have the first design and don't if you have the second. Second design supposedly has these "alignment tabs" (#1):

These tabs look like they are shown in the crankshaft, because the seal is definitely smooth all the way around.

Anyway, the GM manual also has you check the plastic oil galley dumbell protrusion. It also tells you you have to use the crankshaft end guide cone, J-41479-2A, when installing the new cover with seal.

Then there is yet another flat plate tool, J-41480, you are supposed to remove the oil pan and align the block and bottom of seal cover/housing with:

Once you have installed this J41480 and torqued it down to align the seal housing/cover, then you take it off and check flatness across the block and the housing/cover.

Anyway, obviously no one ever uses these tools and you can't blame them because they are an insane amount of money, especially for someone DIY'ing and not shop work. Its just really confusing how the manual says there is 2 designs and the second design dosen't have to be aligned horizontally using a tool, then they mention another tool that has to be used to align the housing (I would assume vertically), then there is the "guide cone" tool.

I think the Dorman instructions bypass all the GM special tools by telling you to just install the new cover/housing and seal and just push it on, hand tighten all the bolts, then torque the long 10mm oil pan to housing/cover bolts, then torque the housing/cover bolts. However, Dorman does say you need to use the "alignment cone" (J-41479-2A) tool when installing the cover, but I bet no one DIY'ing uses this either.

Since I am going to be taking this transmission out again and putting back my original one in once I get it built, I guess I will just slap everything back in and hopefully that will be enough miles to see if it will leak or not. From preliminary searching on the forums it seems no one really worries and just slaps the new ones on as well and supposedly they say they are ok.

1FastBrick

iTrader: (17)

I actually have the complete tool kit

The J-41480 is to take the place of the oil pan. All it does is ensure the that the bottom is flush with the pan rails.

You really don't need much to align a rear plate that has a factory seal installed. The factory seal has a plastic retainer in the center that helps match it up and as soon as you start to press the crank through it pops out.

I have never installed the Dorkman Garbage so I can not comment on that.

They key is to put everything on finger tight before torqueing it down.

jclark10

iTrader: (1)

Ok thanks that makes more sense. Even if you have the oil pan on you still have the oil pan gasket and not sure how flat that will push down without really torqueing down, not sure if the long 10mm oil pan to cover/housing bolts torqued to the factory spec of like 10Nm first before you tighten the cover bolts, would be enough to pull it down straight or not against the oil pan gasket.

The dorman seal that was already installed in the cover/housing looks like it was just the seal and no plastic retainer concentric on the inside diameter. Do you think the alignment cone thing that goes onto the end of the crank is necessary, or at least 100% required, when installing a seal and cover?

RB04Av

Looks like you have oil leaking through the flex plate bolts.

LOOK through those holes, you can SEE the rest of the crank up in there, inside of the pan.

The solution is simple: the Permatex/Loctite (sorry, same company with 2 brand names, I forget which brand name they assigned this product to) "high temp automotive thread sealer with PTFE" on the flex plate bolt threads. All 6.

The Dorman rear cover is just fine. Better than OEM for people like us IMO; the OEM was designed for the factory environment, the other was designed for numbnutz in the field, like us (speaking strictly for myself), to install. Neither is "good", "bad", "crap", "garbage", "The Solution", or any of that. It's more about SUITABILITY FOR PURPOSE than "quality".

Like 1Fast says, the key is to assure that all the parts and pieces are LINED UP, before tightening anything down. THIMK CAREFULLY about what has to be lined up with what, like what flat surfaces on 2 parts have to bolt up to a flat surface on some other part, and assure that it happens like that. It's really not that hard. Even without J-59174603-A-YGZ rev 13.5 special tool. The tool might make it easier, but you may be assured, success is attainable without it.

The 2 long bolts are VERY EASY to strip out of the cover. They are NOT "10mm"; their HEAD is 10mm, but the bolts themselves are 6mm. A shade smaller than ¼", with a thread not far from the ¼" fine thread. No matter whose rear cover you have, a Heli-Coil in each of those 2 bolt holes, might not be a bad idea, BEFORE putting the cover on.

jclark10

iTrader: (1)

Thanks for the info. So are the holes drilled into the crank for the flexplate not blind holes? I did see oil coming out of one near the bottom, but I see oil get in spark plug holes, and I see it get in the front of the crank too where the damper bolts too, I just figured it seeps in past the bolt heads and threads overtime?