Rear main side seals

[TurboDave]

In reading various threads it seems to me that packing the side seals full of xxxxx instead of using the rubber inserts is the prefered method.

My question is, what are everybody's opinion on what material/brand to pack in there and more importantly, what's the best way to get it in there to make a good seal that the oil wont penatrate.


I should have added, this is a clean dry short block assembly process.

 

[turbodave231]

Dave,

Guys have success using the side seals and by filling the side grooves with RTV. I really think both ways work, and attention to detail makes the difference between success and failure.

Factory 36 filled the side grooves with RTV when they built our engines. Buick recommended not using RTV for repair. They wanted you to use the side seals.

I think to be successful filling the grooves, you must be 100% oil free and fill 100% of the cavity. Avoiding air pockets is important. I've taken lots of engines apart and found the RTV had air pockets filled with oil.

I personally have success using the Felpro rear main kit using the included side seals.

As far as RTV product. I like Permatex Ultra Black, or the Great Stuff. If you are going the route of filling the side grooves, use an aerosol product. I think it would be easier to get a 100% fill of the groove without having to squeeze the tube.

Good Luck, Happy Motoring!

Dave

 

[BobbyBuick]

Dave,I have alwayed used a small flat washer on the long tube to shut off the surface you are filling in to force the silicone into the groove.I also take a pipe cleaner dipped in water and give it a push into the groove to help it cure and remove air bubbles.then refill again .Never leaked

 

[TurboBuRick]

Dave,

I have had sucess with grey Permatex. Rigid high-torque rtv silicone gasket maker.
I'm sure that the black stuff would work too.

GL

 

[gsgns4me]

I bought a Valco brand tube grip from Jeg's years ago. Money well spent. didn't care much for the sealer that came with it, but the tool is excellent.

Valco Products

 

[TurboDave]

Anybody got a neeto drawing of exatly where and how much RTV to smear on the bottom side of the rear cap to seal it?

 

[83ttypecooled]

sealing

Hi,
I assembled my engine with potential leaks in mind. The viton seals were installed, around the crank and against the main cap. I also hammered in the nails that were provided.Finally,I applied The right stuff AVS to the block side of the thick cork gasket I bought from Kirban,and torqued it down to 120 inch-pounds. This is way below the torque that is recommended,but I feel that it is right with the gasket I am using. The end result is that after 2 years and a few thousand miles, I have no leaks. I hope it stays that way. We shall see....

 

[LOT]

Think about this way

Using Ultra black sealant--holding cap in hand--starting @ the mating area--fill slot half way to top with sealant--insert side tabs (Felpro hard tabs) in slot up to sealant--install cap and torque to desired value--using small mallet drive side tabs down forcing sealant out the sides--drive all the way down or untill they stop--cut off excess--wipe any sealnat excess off--drive nails in side. Now you know the slot is full. BTW, I use a paper thin coat of Loctite 518 on the mating surface of cap ( or block--not both).

 

[TurboDave]

Using Ultra black sealant--holding cap in hand--starting @ the mating area--fill slot half way to top with sealant--insert side tabs (Felpro hard tabs) in slot up to sealant--install cap and torque to desired value--using small mallet drive side tabs down forcing sealant out the sides--drive all the way down or untill they stop--cut off excess--wipe any sealnat excess off--drive nails in side. Now you know the slot is full. BTW, I use a paper thin coat of Loctite 518 on the mating surface of cap ( or block--not both).

Very interesting technique!! I like the sounds of this.

I don't remember seeing Loctite 518 in my local parts stores, does it have an over the counter equivalant? or is it real important to use it exactly...? (Just finished a search and it's an anaerobic sealant which should cure well in tight quarters).
And what part of the mating surface do you cover? I'll assume I shouldn't get it near the bearing.

I've got the crank and rods all installed (mains all clearanced at about .0016ish and rods at about .0018ish), but pulled the rear cap off because I was pretty sure I did a bad job. So now I have the cap REAL clean, and I think I better pull out the block crank seal and lube it good and try and re-install it. Hopefully with lube it'll slide back under the crank easilly enough (probably wont though)

 

[pdzz]

I've always used GM assembly adhesive,it's some type of RTV. Never had a leak. I've torn engines back down, for other reasons, found it difficult to remove the cap!! Just make sure RTV is warm, soak it in hot water. Phil.

 

[TurboDave]

Here's a couple pix I could use help with.

This is an overall.

The bottom pix just shows a closeup of the rear. I don't have a "drawing" program to "mark up" the photo, if someone has one, show me where the best place is to lay down the thin layer to seal the bottom of the cap.

 

[LOT]

I'll try

See the slot in the block where the slinger on the crank runs--from there back to the end of block--over to, but not up the sides. It would be like the back half of the mating surface (cap to block). Hope this makes sense. Loctite 518 is a non hardening case to case sealer. I suppose any sealant would work. I always used 518 because that is it's purpose. Best of luck.

 

[TurboDave]

See the slot in the block where the slinger on the crank runs--from there back to the end of block--over to, but not up the sides. It would be like the back half of the mating surface (cap to block). Hope this makes sense. Loctite 518 is a non hardening case to case sealer. I suppose any sealant would work. I always used 518 because that is it's purpose. Best of luck.

You mean where I put the RED?

I was thinking where the YELLOW is, but that sounds wrong?

 

[gnxtc2]

When you install the seals that go around the crank, position one end approximately 1/4" below the parting surface. The other end is going to stick up. Now do the opposite on the cap. Basically you don't want the seal to be even with the parting surface.

Next put the anaeorbic stuff (red jelly stuff) on the parting line. Don't use RTV here, it won't dry and the oil will pass through.

I use the rubber side strips and the nails. I put some RTV down the side cavity and let the rubber strip push the RTV into the crevices.

It doesn't matter gray or black RTV, used both in the past.

Billy T.
gnxtc2@aol.com

 

[TurboDave]

Take a look at my picture in the previous post. You can see the crank seal is offset about 1/4".

Notice the different colors I added. Do either of them correlate to what you said about the "parting line"?

When you install the seals that go around the crank, position one end approximately 1/4" below the parting surface. The other end is going to stick up. Now do the opposite on the cap. Basically you don't want the seal to be even with the parting surface.

Next put the anaeorbic stuff (red jelly stuff) on the parting line. Don't use RTV here, it won't dry and the oil will pass through.

I use the rubber side strips and the nails. I put some RTV down the side cavity and let the rubber strip push the RTV into the crevices.

It doesn't matter gray or black RTV, used both in the past.

Billy T.
gnxtc2@aol.com

 

[gnxtc2]

Take a look at my picture in the previous post. You can see the crank seal is offset about 1/4".

Notice the different colors I added. Do either of them correlate to what you said about the "parting line"?

Yes, I put the anaerobic stuff on the parting line. You can put it where your red and yellow markings are.

Billy T.
gnxtc2@aol.com

 

[TurboDave]

You mean where I put the RED?

I was thinking where the YELLOW is, but that sounds wrong?

Any thoughts Lee??

 

[LOT]

yes

Where your yellow mark is--I do that whole area up to where the red is---do your yellow mark on over to the vertical sides and on out to end of block.---- Very important!!!!--only a paper thin coat--you only want to fill any voids---as someone already mentioned and I forgot--coat the side seal with sealant. If you do as we have talked about here, I am highly optimestic it will not leak !!!!! Best of luck.--Lee

 

[bad V6]

When I replaced the rear main in my stock engine, I trial fit the nails and cut them prior to installing them. When they bottomed out all that was left to do was some cleanup and prep for the gasket and oil pan.

 

[bison]

I always used 518 because that is it's purpose. Best of luck.

I use this stuff often. I do not use a gasket between the turbo and return line and often leave out the plenum gasket in favor of the 518. I use no gasket for the water pump and 518 there also.