[76TA462]

Its been a loooong time since I changed the rear end lube. I know I used a blue Felpro gasket but cant remember if I used any RTV. Is a gasket only fine. Or is RTV needed, and if so what type, and which side of gasket or both sides. Thanks.

[gtokid1968]

Make sure the cover is flat and you can use almost any type of silicone to seal it up,
Make sure it is oil free and it should be good as new. In my experience anyway.

[Brian Baker]

I always use a very light skim coat on both sides of the gasket.

[steve25]

I have not used a gasket back there in 30 years, just Blue form-A gasket, you just need to get both sealing sides 100% free of oil and the let the applied bead of sealer start to set up pretty good before bolting the cover on.

I do the same with valley pan gaskets.

[76TA462]

Thanks a bunch. I'll be using AC Delco additive. How many quarts does the differential need. OEM Safe-T-Trac.

[76TA462]

LOL. Quarts of 80W90 that is.

[RocktimusPryme]

Ive done several rear ends recently of different makes with the fel pro paper gasket and a coating of the red Permatex spray tack. No leaks.

I love that stuff. I have both the copper for heat parts and the regular red stuff. Works great, less mess than RTV.

[David Jones]

Pretty much, if both sides are pretty clean and mostly flat and you take some kind of care tightening things down, you can do what you like. I've cut my own, used the blue Felpro dry or wet and just used stuff out of a tube. Never a leak.

[SRR]

Use the gasket. Use gasket sealer on the cover side only and lightly grease the other side. This way the next time you take it off you won't have to scrap on the diff. It's just easier to clean the cover off the car. If you use just sealer, good luck getting the cover back off next time without bending the cover. Unless it's one of those aluminum jobs.

[Schurkey]

Use RTV Silicone INSTEAD of a gasket, not applied TO a gasket.

There's plenty of gasket sealers/gasket adhesives. Silicone is NOT the proper product. Gasgacinch, High Tack, Indian Head, Copper Coat...the list goes on and on.

Either silicone the cover in place, or use a gasket. If you're using a gasket, don't use sealer on both sides. If everything is in good condition--no rust pits, cover not warped, etc--you probably don't need a sealer on that gasket at all.

[chrisp]

Permatex 81182 Gear Oil RTV Gasket Maker

[Formulajones]

I use a very thin coat of permatex on the gasket to help things. I find those diff gaskets so thin they don't have much if any crush to them to seal. Especially if there are imperfections. I've used them dry, and while sometimes I get away with that, most times it still ends up in a very small drip or a diff with a wet area around the bottom that seeps and drives me nuts. So rather than waste all the gear oil and posi additive to replace another gasket, I use a very small amount of sealer on it for piece of mind. Do it once and done.

[Grand73Am]

Originally Posted by 76TA462

Thanks a bunch. I'll be using AC Delco additive. How many quarts does the differential need. OEM Safe-T-Trac.

Capacity spec of the 2nd gen TA is 4-1/4 pints. So, 2 quarts gear oil plus 4 oz. limited slip additive equals the capacity and works well. Also, I agree with SRR's advice for using a gasket with a little gasket adhesive on the cover side, and lightly grease the axle side. Torque spec for the bolts is 30 lb/ft.

[77 TRASHCAN]

The last several diff gaskets I have used were either Fel Pro or GM. THey were all thick enough to handle most imperfections in the cover. I use RTV on both sides of the gasket. It helps seal, helps hold the gasket in place and allows easy removal in future.
I pour in the bottle of GM additive first, then fill to the bottom of the hole. I then cover the bottom half of the hole with a finger and put a little oil in. I've never had any vent issues doing this. I just thinks it good to have as much oil as possible. When diff oil leaks develop, a person usually never notices them in time. The extra oil could help with this, IF EVER needed, or help with cooling.

[mgarblik]

Originally Posted by Schurkey

Use RTV Silicone INSTEAD of a gasket, not applied TO a gasket.

There's plenty of gasket sealers/gasket adhesives. Silicone is NOT the proper product. Gasgacinch, High Tack, Indian Head, Copper Coat...the list goes on and on.
tech literature
Either silicone the cover in place, or use a gasket. If you're using a gasket, don't use sealer on both sides. If everything is in good condition--no rust pits, cover not warped, etc--you probably don't need a sealer on that gasket at all.

That's right out of the Fel-Pro gasket literature and most automotive textbooks. Both Fel-Pro and Victor do not recommend using RTV on top of gasket material. Only to fill gaps or as a gasket substitute. I understand many, many people use different techniques. Rear covers, I personally use a gasket and put it on clean and dry. Or use RTV and no gasket. Equal good results.

[mchell]

I prefer these. Don’t know what they have for 10 bolts, but they are the shi&$ !!

[Half-Inch Stud]

Do a nice Cover install, and re-discover that the Pinion Seal leaks.

[1968GTO421]

Originally Posted by Half-Inch Stud

Do a nice Cover install, and re-discover that the Pinion Seal leaks.

Ain't it the truth

['ol Pinion head]

Love the OEM GM gray differential gaskets. Am out of NOS for 8.5 cutout cover housings & for 12 bolt car. Will be listing NOS cover gaskets for sale for '65-70 P series (big Pontiac) as seldom build that style rear anymore.

[242177P]

Originally Posted by mchell

I prefer these. Don’t know what they have for 10 bolts, but they are the shi&$ !!

Looks like a nice gasket, and a nice selection. Here's the 8.2.
https://www.lubelocker.com/collectio...axle-llr-82bop